AGM Rattler-C V2 50-640 Thermal Clip-On Attachment

The AGM Rattler-C V2 50-640 is a front-mounted thermal clip-on a thermal imaging unit that attaches in front of an existing daytime riflescope to give it thermal imaging capability. The day scope's reticle, magnification, and zero stay in use; the Rattler-C V2 projects the thermal image through the day scope's objective, so a hunter looks through the day scope as normal and sees a thermal image in place of (or in addition to) the daytime view.

The 50-640 sits at the 640 sensor tier of AGM's Rattler-C V2 clip-on family. It pairs a 640—512 thermal sensor built on a 12 μm pixel pitch with NETD rated at less than 20 mK at 25°C to a 50 mm F/1.0 objective lens, delivering 2,600-yard detection on a 6-foot target through a 0.39-inch 1024—768 OLED display at 50 Hz refresh.

The Rattler-C V2 lineup at Thermal Bros how the 50-640 fits

Thermal Bros carries two clip-ons from the AGM Rattler-C V2 family. They're curated as a good/better pair the 35-384 as the accessible entry into the V2 clip-on platform at the 384 sensor tier, and the 50-640 as the step-up at the 640 sensor tier for hunters who want higher pixel count and the larger 50 mm lens.

• AGM Rattler-C V2 35-384 35 mm lens, 384—288 sensor, <20 mK NETD, 7.5° — 5.6° field of view, 1,800 yd detection range. The 384-tier option.
• AGM Rattler-C V2 50-640 50 mm lens, 640—512 sensor, <20 mK NETD, 8.8° — 7.0° field of view, 2,600 yd detection range. The 640-tier option.

The two clip-ons share the V2 platform 50 Hz refresh rate, 1— optical magnification, 0.39-inch 1024—768 OLED display, shot-activated and manual recording with audio, stadiametric distance measurement, Hot Track, Wi-Fi hotspot via the AGM Connect app, IP67-rated build, and the NE-4400 rechargeable battery system. Sensor resolution and lens size are what separate them.

Step up to the 50-640 from the 35-384 when 640-tier sensor resolution, the 2,600-yard detection range, and the wider field of view are the deciding factors.

Why a thermal clip-on instead of a dedicated thermal scope

A clip-on is a different solution to the night hunting problem than a dedicated thermal rifle scope.

A dedicated thermal scope replaces the day scope entirely. The hunter mounts the thermal, zeros it to the rifle, and uses the thermal's own reticle and magnification. One scope, one rifle, one zero.

A clip-on attaches in front of the existing day scope. The day scope's reticle, magnification, and zero stay in use the clip-on just projects the thermal image into the day scope's optical path. The same clip-on can move between rifles, mounting in front of whichever day scope is on the rifle for that hunt, without re-zeroing the day scope each time.

For hunters running thermal on a single rifle that hunts only at night, a dedicated thermal scope is usually the cleaner solution. For hunters who use the same rifles in daylight and want thermal capability available across one or more existing setups without buying a separate thermal scope for each, a clip-on lets one thermal unit serve multiple rifles.

Why the 640 sensor at sub-20 mK NETD matters

The 640—512 sensor delivers 327,680 pixels of thermal data, paired with a 12 μm pixel pitch and NETD rated at less than 20 mK at 25°C. The 640 sensor tier carries roughly three times the pixel count of a 384 sensor (110,592 pixels), which translates to finer thermal detail, cleaner edge definition on warm bodies against cooler backgrounds, and easier target identification at longer ranges.

Lower NETD means the sensor can resolve smaller temperature differences before electronic noise washes them out. The <20 mK rating is the same sensitivity tier as the Rattler-C V2 35-384 what changes at the 640 tier is pixel count, not sensitivity. The two specs work together: more pixels resolve more detail in the scene; better sensitivity holds image quality as conditions get marginal.

Why the 50 mm objective lens earns its place

A 50 mm F/1.0 objective gathers more thermal signal than the 35 mm lens on the Rattler-C V2 35-384, which is what enables the longer 2,600-yard detection range on a 6-foot target.

The 50-640 also carries a wider field of view than the 35-384 8.8° — 7.0° versus 7.5° — 5.6°. That's counterintuitive at first since a larger lens usually means a narrower field, but the math works out the other way here: the 640—512 sensor is physically larger than the 384—288 sensor, and pairing a larger sensor with a larger lens gives the 50-640 more angular coverage at base. The result is a clip-on that combines longer reach and wider scanning capability than the 35-384 at the cost of size, weight, focus range, and price.

The 50-640's focus range is 10 m to infinity (versus 2 m to infinity on the 35-384). Targets closer than 10 m won't focus through the clip-on.

Why the Rattler-C V2 platform is different

Three things define the Rattler-C V2 platform on the 50-640:

• 1— pass-through optical design. The clip-on operates at 1— optical magnification. The day scope behind it provides the actual magnification whatever the hunter has in the day scope is what they get when the clip-on is mounted. No second magnification stack, no compounded zoom degradation.
• NE-4400 dual-battery field-swap system. Two NE-4400 rechargeable lithium-ion batteries ship in the box. The battery compartment is built for fast field swaps pull the depleted battery, drop in the charged spare. 9 hours of runtime per battery at 25°C with the Wi-Fi hotspot off. Note that the 50-640's runtime per battery is shorter than the 35-384's 11 hours the higher-resolution 640 sensor draws more power.
• Onboard recording with stadiametric distance measurement and Hot Track. Manual photo, video, and audio recording, snapshot capture, and shot-activated video recording are built in, saving to 16 GB internal EMMC. AGM's stadiametric distance measurement function and Hot Track feature are both listed in the published spec.

What you get with the Rattler-C V2 50-640

• 640 — 512 thermal sensor with 12 μm pixel pitch. The 640 sensor tier on the Rattler-C V2 platform roughly three times the pixel count of the 35-384's 384—288 sensor.
• NETD <20 mK (25°C, F#=1.0). Sensor sensitivity that holds image quality in marginal heat differentials and adverse weather.
• 50 mm F/1.0 objective lens. The larger lens option in the Rattler-C V2 lineup, gathering more thermal signal for the longer detection range.
• 1— optical magnification. Day scope provides the magnification; no compounded zoom path through the clip-on.
• 2,600-yard detection range on a 6-foot object.
• 50 Hz refresh rate for smooth real-time imaging on moving targets.
• 0.39-inch OLED display, 1024 — 768.
• 8.8° — 7.0° field of view wider than the Rattler-C V2 35-384.
• 10 m to infinity focus range.
• 22 mm exit pupil; 10 mm eye relief.
• Color palettes: Black Hot, White Hot, Red Hot, Fusion.
• Cold and Warm scene modes to tune the sensor for the environment.
• Flat field correction: Auto, Manual, External Correction.
• Stadiametric distance measurement.
• Hot Track.
• Shot-activated video recording with manual photo, video, and audio recording also supported.
• Snapshot capture.
• Wi-Fi hotspot with smartphone streaming and file transfer via the AGM Connect app.
• 16 GB internal EMMC storage.
• NE-4400 dual-battery field-swap system. Two rechargeable Li-Ion batteries included; 9 hours per battery at 25°C; USB Type-C charging.
• External power supply compatibility via USB Type-C (5 VDC, 2 A) for use with an external power bank.
• IP67-rated waterproof and dustproof construction.
• Operating temperature range -30°C to +55°C (-22°F to 131°F).
• AGM 5-year manufacturer warranty.

Who the Rattler-C V2 50-640 is built for

• Hunters who already run a daytime riflescope setup they want to keep using and want to add 640-tier thermal capability on top of it
• Hunters who use the same thermal unit across more than one rifle, with adapter rings sized to fit each rifle's day scope objective
• Hog and predator hunters whose engagement window calls for 640-tier sensor resolution and the 2,600-yard detection range a 50 mm lens enables
• Buyers who want the wider field of view the 50-640 carries useful for scanning open country or pasture
• Hunters stepping up from a 384-tier thermal scope or clip-on who want the additional pixel count and reach
• Buyers willing to accept the larger physical footprint, heavier weight, longer minimum focus distance (10 m), shorter battery runtime, and higher price point in exchange for the 640 sensor and 50 mm lens performance

The Rattler-C V2 50-640 is less ideal for hunters who don't already have a daytime riflescope they want to keep using (in which case a dedicated thermal scope is usually the cleaner solution), for hunters who need to focus on targets closer than 10 m, or for buyers whose hunting style fits within the 384 sensor tier and the more accessible price point of the Rattler-C V2 35-384.

Full specifications

• Thermal sensor: 640 — 512, 12 μm pixel pitch
• Sensor architecture: 12 μm VOx uncooled focal plane array
• NETD: <20 mK (25°C, F# = 1.0)
• Objective lens: 50 mm F/1.0
• Optical magnification: 1—
• Field of view: 8.8° — 7.0°
• Detection range: up to 2,600 yards (6-foot object)
• Display: 0.39-inch OLED, 1024 — 768
• Refresh rate: 50 Hz
• Focus range: 10 m to infinity
• Exit pupil: 22 mm
• Eye relief: 10 mm
• Color palettes: Black Hot, White Hot, Red Hot, Fusion
• Scene modes: Cold, Warm
• Flat field correction: Auto, Manual, External Correction
• Distance measurement: stadiametric
• Hot Track: yes
• Standby mode: yes
• Snapshot capture: yes
• Wi-Fi hotspot: yes (AGM Connect app)
• Recording: photo, video, audio; shot-activated and manual
• Internal storage: 16 GB EMMC
• Battery system: NE-4400 rechargeable Li-Ion (two included), field-swappable
• Battery life: 9 hours per battery (25°C, hotspot off)
• External power: 5 VDC, 2 A, USB Type-C
• Operating temperature: -30°C to +55°C (-22°F to 131°F)
• Construction: IP67 waterproof and dustproof
• Dimensions: 7.7 — 2.9 — 2.7 in (196 — 73 — 68 mm)
• Weight: 1.2 lb (0.55 kg)
• Mount: included
• Warranty: AGM 5-year manufacturer warranty

In the box: thermal clip-on, mount, two NE-4400 rechargeable batteries, battery charger, USB cable, lens cloth, owner's manual, carrying case.

Frequently asked questions

Where does the 50-640 fit in Thermal Bros' Rattler-C V2 lineup?

Thermal Bros carries two clip-ons from the AGM Rattler-C V2 family. The 35-384 is the 384-tier option with a 35 mm lens, 7.5° — 5.6° field of view, and 1,800-yard detection. The 50-640 is the step up to the 640 sensor tier 640—512 sensor on a 50 mm lens, 8.8° — 7.0° field of view, 2,600-yard detection. Step up to the 50-640 when 640-tier sensor resolution, the wider field of view, and the longer detection range are the deciding factors.

What's the difference between the 50-640 and the 35-384?

Sensor, lens, field of view, detection range, focus range, battery life, size, and weight. The 50-640 carries a 640—512 sensor on a 50 mm objective lens with an 8.8° — 7.0° field of view and 2,600-yard detection. The 35-384 carries a 384—288 sensor on a 35 mm lens with a 7.5° — 5.6° field of view and 1,800-yard detection. Both share <20 mK NETD, the same display, and the same V2 platform features. The 50-640 has a wider field of view than the 35-384 counterintuitive with the larger lens, but the larger sensor combined with the larger lens delivers more angular coverage at base. The 50-640's minimum focus is 10 m (vs. 2 m on the 35-384), its battery runs 9 hr per charge (vs. 11 hr), it weighs 1.2 lb (vs. 1.19 lb), and it's larger overall.

How is a thermal clip-on different from a dedicated thermal scope?

A clip-on attaches in front of an existing daytime riflescope. The day scope's reticle, magnification, and zero stay in use the clip-on projects the thermal image through the day scope. The same clip-on can move between rifles, mounting in front of whichever day scope is on the rifle. A dedicated thermal scope replaces the day scope, has its own reticle and magnification, and zeros to the rifle on its own. Clip-ons are typically the better fit for hunters running multiple rifles or wanting to keep an existing day scope in use; dedicated thermal scopes are typically the better fit when a single rifle hunts at night only.

Do I need to re-zero my day scope when using the clip-on?

The clip-on uses the day scope's existing reticle and zero. The day scope is not re-zeroed for thermal use. Hunters typically confirm alignment by checking impact on a target after the clip-on is mounted; minor adjustments to the clip-on's image alignment are made through the device menu rather than by changing the day scope's zero.

Will the 50-640 fit my day scope?

The Rattler-C V2 mounts in front of the day scope using an AGM front Q-R adapter sized to match the day scope's objective diameter. AGM offers adapters in multiple sizes (40 mm, 42 mm, 44 mm, 50 mm, 56 mm, 58 mm, 60 mm, and 62 mm) as separate accessories. The adapter required depends on the specific day scope's objective. Confirm objective diameter and adapter size before ordering.

Why won't the 50-640 focus on close targets?

The 50-640's published focus range is 10 m (about 11 yards) to infinity. Targets closer than 10 m will not come into focus through the clip-on. This is a function of the larger 50 mm objective lens larger lenses generally have a longer minimum focus distance than smaller lenses. The Rattler-C V2 35-384's smaller 35 mm lens focuses down to 2 m. For hunters whose engagement distances are well beyond 10 m, this isn't a limit that comes up in the field.

How long does the battery last?

9 hours per battery at 25°C with the Wi-Fi hotspot off. Two NE-4400 rechargeable batteries ship in the box, and the compartment is built for fast field swaps. An external 5 V power bank can also be connected via USB Type-C to extend operating time.

Does the 50-640 record video?

Yes. Manual video and audio recording, snapshot capture, and shot-activated recording are all built in. Files save to 16 GB of internal EMMC storage and can be transferred via USB Type-C or streamed and downloaded over Wi-Fi through the AGM Connect app.

What's the detection range?

AGM publishes 2,600 yards detection on a 6-foot object. Detection is the distance at which the sensor can register that something warm is present it is not the same as identification or shot-placement distance. Practical engagement distance depends on the day scope's magnification, the target size, and conditions.

Is the 50-640 waterproof?

Yes. The clip-on is IP67-rated sealed against dust ingress and rated for water immersion up to one meter for 30 minutes.

What's the warranty?

AGM backs the Rattler-C V2 50-640 with their 5-year manufacturer warranty.