The ThruNite Ti3 is a diminutive but rugged little flashlight that can produce as much as 120 Lumens of brightness on a single AAA battery. It is worth noting that the Ti3 at 18 g (.63 oz) with battery is somewhat lighter than any headlight I have, even my UL MYOG models which start at 52 g (1.8 oz). This weight difference alone makes it worthy of consideration as a piece of ultralight gear. The Ti3 arrived with an explanation that ThruNite has a newer production version coming out shortly.

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Photo: ThruNite

The Ti3 arrived in a small tin box with all the accessories stored away inside under the foam. There’s a clip as shown here and a little clip on some chain, all of which I quickly discarded.

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Instead, I made a loop of fluoro nylon string ( I used 330 mm), large enough to easily slip over my hand but small enough that it would not fall off.

The genius of the Ti3 rests in its size to brightness ratio. A single AAA Lithium battery powers it. The flashlight is only slightly larger than the battery itself. That is TINY! The marginally larger head contains the electronics that handle the modes.

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Features and Specifications

Price 16 USD
LED Cree XP-G2 R5
LED life 20+ years
Length 70 mm (2.75 in)
Diameter 14 mm (.55 in)
IPX-8 waterproof to 2 m (6.56 ft)
Made in China
Weight without battery 12 g (.42 oz)
Weight with AAA lithium battery & string 17.7 g (.62 oz)
Firefly mode 0.04 Lm, 115 hr life
Low mode 12 Lm, 6.3 hr life
High mode 120 Lm, 0.5 hr life

The flashlight first activates in Firefly mode, the lowest power setting with the most extended battery life (115 hours). You can bump it up to a higher power by turning it off and on again quickly. Do that three times, and you get a high power strobe operation. You get back to Firefly mode by leaving the light off for >10 seconds.

You activate the light by screwing the head of the flashlight down onto the body a bit. In effect, you are screwing the contact in the head of the flashlight down onto the battery. This action can be achieved with the thumb and forefinger while the rest of the fingers hold the body of the light. No actual switch or button is required!

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The head of the flashlight is not loose on the body: there is a replaceable O-ring between the two parts which makes the twisting operation smooth and keeps the light waterproof. ThruNite provides a replacement O-ring. It was hard to measure, but my best guess is 9 x 1 mm. ThruNite recommends a minimal amount of silicone grease when replacing the O-ring.

You could compare the Ti3 with any of the button flashlights on the market – the ones generally based on a CR2032 coin cell battery. Button flashlights are smaller and lighter, but we would be talking about just a few grams difference here –  in one case 16.5 g (.58 oz) vs. 17.7 g (.62 oz). The big difference to my mind is the expected life of the battery. The button cells, typically CR2032, are rated at 250 at a trickle discharge rate, significantly less at a flashlight discharge rate. Those button batteries are designed for low-power uses. The AAA Lithium battery, on the other hand, is rated at 1250 at a significant discharge. The official specifications don’t go as low as the Firefly mode. The AAA battery has much more guts.

Field Testing

I found the Ti3 extremely simple to use in practical situations.  I was able to quickly orient it in the dark and activate it with one hand. Firefly mode is all one would need in a tent –  it is quite bright. Outside the tent, the Firefly mode is still bright enough for casual excursions, while the battery life is long enough that I didn’t feel the need to keep turning it off and on. I just let it dangle from my wrist on the string loop.


The Ti3 is a featherweight flashlight that punches far above its class.  The ease of use, powerful AAA battery, and rugged construction are all attractive features. The holding loop was easy to modify and the Lumens provided in the low power Firefly mode are more than adequate for interior tent use and casual after dark wanderings. On top of all that, my wife said it best.

“It’s cute!”

Where To Buy


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