These should last a good long time but as they’re not user-replaceable, you have to send the light back to Nitecore or dispose of it if they ever fail. In Tactical Mode we can choose the desired level by briefly pressing the Mode button while holding the Power button to scroll through the following brightness levels: ULTRALOW - LOW - MID - HIGH. International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions. Equipped with the latest TurboReady™ Technology, the NITECORE TM9K is an ultra compact tactical flashlight to emit a max output of 9,500 lumens with a built-in 5,000mAh Li-ion battery and the USB-C charging port. At the bottom of the TM20K we find the round-shaped metal power button, to turn on the flashlight constantly (Daily mode) or momentarily (Tactical mode).

If you need a very bright flashlight to use in every condition (thanks to its IP68 rating) then this is the flashlight for you. With the CNC machined unibody design, the TM20K is solid and durable featuring ambidextrous tactical buttons specially designed for tactical activities. I like the controls of the TM20K, they were carefully thought through and as a user you quickly understand how the light works.Those Li-Ion batteries (in smartphones) are guaranteed to have at least 80% of original capacity after 500 recharges, so roughly 2 years. One of the most important features for a light like this is the lockout; yes the ‘not outputting any light’ feature. This size just barely still fits in a large (jacket) pocket, but thanks to the long clip you can also attach it to your jeans pocket or belt. TM20K is a tactical flashlight built with unibody CNC technology with an ambidextrous control system (UI).

The light is clearly designed for tactical use, using 1 of the main modes the bulk of the time, then occasionally jumping to the blinding 20,000 lumens for a few seconds at a time. Something that might be a ‘pro’ for one user can be a ‘con’ for another, so the comments are categorised based on my requirements. It is powered by built-in rechargeable 21700 Li-ion batteries that charge via a USB-C port on the tail of the light, and is compatible with Quick Charge (QC) adapters for fast charging. Then moving outdoors with the same modes (around the 2,000 Lumen level), and then with the same exposure, the Turbo output.Probably lighter than you expect a 20k lumens flashlight to be, but it "gets" heavier the more you hold it. The tactical button is actually a 2-sided rocker switch, so you can press to either the left or the right. The beam it emits in addition to being remarkable in TURBO also has an opening angle of almost 180 °, really impressive. The Low level (1,050 lumens) has a constant trend for about 4 hours before starting the descent that leads to the TM20K switching off after 4 hours and 26 minutes.

Here you once again see the effect of the different options the TM20K has to offer: focused in between the trees, or broad light at a short distance and illuminating almost everything at full power. The TM20K will head stand, tail stand and stay put when lying sideways, thanks to its flat surfaces.Reference readings are taken to ensure the filter factor is correct, and a set of measurements were taken. years ago our dog got lost in the forest (probably someone stole it, but anyway) and we were looking for him for 5 days, day and night, and I was using Imalent DM70, because it has 21700 battery and good brightness. Bought this as a gift for a naturalist to help them identify some species of lichens and moths so I can't comment on actual use. Haven't used it much (yet); however, it appears to be everything promised and is one "BRIGHT" light. The toggle switch can lock the TM20K for transport or carry, set it to daily mode for constant illumination, or tactical mode for momentary illumination.