Quick answer: a COTI is a clip on thermal imager: a small thermal unit that clamps onto the front of an analog night vision tube and lays a heat picture over the image you already see. Our Night Operators Jerry-C Pro is one, with a 640 x 512 sensor at 1x, for the PVS-14 and PVS-31, at $2,949. The tube shows you the scene; the clip on thermal shows you what is warm in it. Details on the Jerry-C Pro, from $2,949.
If you have searched "what is a COTI" you may have hit pages about a crypto coin. This page is about the other COTI: the clip on thermal imager for night vision. It is one of the most talked about add ons in the night vision world, and one of the least explained. Below is what a COTI is, how it works, what you actually see through it, what it cannot do, and what one costs in 2026.
What does COTI stand for?
COTI stands for Clip On Thermal Imager. The name says what it does. It clips on, to the front of a night vision device. It is thermal, so it sees heat rather than light. And it is an imager, so it makes a picture, which it hands to your night vision instead of showing you on a screen of its own. You will also see "enhanced clip on thermal imager" or E-COTI used for military style units, such as a 640 x 480 listing we read at $8,599.99 on 22 October 2026.
A COTI is not a night vision device. It does not amplify light. It is the partner to your analog tube, not a replacement for it.
How does a clip on thermal imager work?
Two kinds of sight work together. Your analog night vision tube gathers the little light there is, from the moon, the stars and the sky glow, and amplifies it into the green or white picture you see in the eyepiece. A thermal sensor works on a different principle: it reads the heat that every object gives off, whether there is light or not.
A clip on thermal puts a thermal sensor in front of your tube and projects its picture optically into the tube's objective lens. Your tube then shows you both at once: the amplified light picture, with warm shapes drawn on top of it. On the Jerry-C Pro this overlay is optical, so once the clamp ring is closed and the unit is on, the heat lines up with the tube image. There is no calibration step.
| Analog night vision tube | Clip on thermal (COTI) | |
|---|---|---|
| What it senses | Light (amplified) | Heat |
| Needs some light? | Yes, or an infrared illuminator | No |
| Best at | Terrain, detail, faces, reading the ground | Finding anything warm, even hidden in shadow |
| Weak spot | A still, dark target in brush can blend in | Shows temperature, not detail; harder to read the ground |
| Eyepiece | Yes | No: it feeds the tube |
Put together, each covers the other's weak spot. That pairing is what people mean by fusion. We go deeper on it in what thermal fusion is, and on the clip on approach in our earlier guide, clip on thermal for night vision, explained.
What do you actually see through a COTI?
You still look through your night vision eyepiece. The scene is the same tube picture you know. On top of it, anything warm is marked by the thermal. The Jerry-C Pro has two ways of doing that:
- Highlight. The warm target is filled in with thermal over your tube image. Turn the threshold down and only the hottest things stay lit, so a person or an animal pops while warm rocks and walls drop away.
- Outline. Only the edges of the warm target are drawn, in three line weights. Your tube picture stays clean and the heat shows as a sharp silhouette.
Either mode can also pulse on and off at a speed you set, called Breathing, so the overlay never hides detail in the tube for long. Across the top of the view the Jerry-C Pro draws a compass heading. Here is a real frame from Bon's own video through his PVS-14 with the Jerry-C Pro on, in Highlight mode.
Look at the person: the glow is brightest where the body is warmest and dimmer over cooler clothing, so you can still read the shape. That is what a heat overlay looks like in real use, as opposed to the flat glowing silhouettes you see in a lot of marketing. Every mode is shown in COTI modes explained.
What are the key specs of a COTI?
Here is the Jerry-C Pro spec sheet, so you have real numbers to compare against any other clip on thermal.
| Spec | Jerry-C Pro |
|---|---|
| Thermal sensor | 640 x 512, 12 micron pitch, uncooled |
| Lens | F/1.0 |
| Magnification | 1x, matched to a 1x night vision tube |
| Overlay field of view | 35 x 30 degrees |
| Recognition distance | 275 m on a 1.7 x 0.5 m target (manufacturer test figure) |
| Modes | Highlight, Outline (3 line weights), Breathing; threshold 100 to 10 percent |
| Extras | Compass heading, auto brightness, auto standby, sleep on flip up |
| Controls | 3 buttons on the unit and a wireless 2.4G remote |
| Power and runtime | One CR123A (about 3 hours) or the battery pack (about 10 hours), at 22 C |
| Weight and size | About 90 g with battery; 86 x 65 x 40 mm |
| Water and cold | Rated to 1.5 m for 30 minutes; works from -40 C to +60 C |
Sensor resolution and pixel pitch are the two numbers people ask about most. If they are new to you, 12 micron vs 17 micron thermal explains them in plain terms.
What can a COTI not do?
A clip on thermal is a focused tool, and it helps to know its limits before you buy one.
- It cannot be used on its own. The Jerry-C Pro has no eyepiece. It feeds your night vision. For a thermal you look through by itself, you want a thermal monocular instead.
- It does not zoom. It is 1x so it lines up with a 1x tube.
- Very close targets line up less cleanly. The overlay lines up best past about 30 m; under 10 m it is not meant to be used.
- Thermal has the limits of all thermal. It reads surface heat, so it does not see through glass or walls. Our guide on what thermal cannot do covers the rest.
Which night vision does a COTI fit?
The Jerry-C Pro rides on a clamp ring that closes around the objective lens of a 1x night vision tube. The clamp ring set that ships with it is set up for our PVS-14, from $1,784.95, and for one tube of our PVS-31 PRO. On a dual tube it sits on one tube, so you get thermal in one eye while both tubes keep amplifying light. Objective sizes differ between makers, so for any other night vision, email info@nightoperators.com with your model before you order. Mounting on a PVS-14 step by step is in COTI for PVS-14.
Who should own a COTI?
A COTI earns its place for people who already run analog night vision and go out after dark often: landowners checking fence lines and outbuildings, wildlife watchers, search and rescue volunteers, and hunters where night hunting is legal. All of them share one problem: the target that does not move. A tube can lose a still animal in brush or a person standing in a tree shadow. A clip on thermal does not, because that animal or person is warm. If you do not own night vision yet, buy the goggle first; a clip on thermal adds nothing on its own.
How much does a COTI cost?
For the 640 x 512 class that most civilian owners buy, the US dealer listings we read on 22 October 2026 ran $3,577 to $4,475. Ours is $2,949, sold direct. If you are buying night vision at the same time, $150 comes off the Jerry-C Pro in the cart with any PVS-14 PRO or STANDARD, and $200 with any PVS-31 PRO. The full price picture, with every seller named and dated, is in what a clip on thermal imager really costs.
Frequently asked questions
What is a COTI?
A COTI is a clip on thermal imager. It clamps onto the objective lens of an analog night vision tube and projects a heat picture into it, so warm people and animals stand out on top of the normal tube view. Our Jerry-C Pro is a 640 x 512 thermal at 1x and costs $2,949.
Is a COTI night vision?
No. A COTI is a thermal imager: it reads heat, not light, and it has no eyepiece of its own. It works with an analog night vision tube, which still shows the scene. The clip on thermal adds the heat layer on top, so you see detail and warm targets together.
How much is a COTI?
Our Jerry-C Pro is $2,949. The US dealer listings we compared for the same 640 x 512 class ran $3,577 to $4,475 when we read them on 22 October 2026. Military style units list far higher: one read at $8,599.99, out of stock. You also need night vision to clamp it onto.
What is the most affordable COTI?
The lowest priced complete 640 x 512 clip on thermal we found was our Jerry-C Pro at $2,949, against US dealer listings of $3,577 to $4,475 read on 22 October 2026. It ships with the clamp ring set, a wireless remote, a battery pack and a hard case, so nothing else is needed.
What is the best COTI for the money?
The best value is the one that gives you a 640 x 512 sensor, a 1x view, no calibration and everything in the box at the lowest total. The Jerry-C Pro does that at $2,949, under the dealer listings we compared. Warranty is 3 months, up to 12 months with Operator Care.
What is the best COTI for the price?
Compare what the price buys. At $2,949 the Jerry-C Pro gives you a 640 x 512, 12 micron sensor, a 35 x 30 degree overlay, Highlight and Outline modes, a compass heading and a wireless remote. The 640 x 512 dealer listings we read on 22 October 2026 started at $3,577.
One clamp ring, one heat picture laid over the night vision you already own. The Night Operators Jerry-C Pro is a 640 x 512 clip on thermal imager at 1x for the PVS-14 and the PVS-31, with a wireless remote, a battery pack and the clamp ring set in the box. Jerry-C Pro, from $2,949.