I purchased 4 of these to have as a spare set for my TM28. I use my TM28 quite a lot for wildlife spotting in my local area, and this involves quite a bit of turbo/6000 lumen use and as such I can exhaust one set of batteries and then need another to continue using. I looked around at other batteries (including flat topped 18650 but unfortunately these would not work for me despite using the supplied flat top adapter that comes with the TM28). A lot of the other (none Nitecore batteries) were out of stock on their respected website (it was right after Christmas and New Year so it was to be expected I suppose) or they were less than the 10A continuous discharge rating that are needed for the turbo/6000 lumen option of the TM28. After experiencing great results and run time with these same batteries that came with the TM28, it made sense for me to purchase the exact same batteries for a spare set. After looking around at suitable specification none Nitecore batteries, the Nitecore ones were only £4-£5 more expensive per battery than a suitable none Nitecore battery. I feel this is not much when considering it will be quite a number of years until I need to purchase new batteries again. These Nitecore TM28 batteries are absolutely brilliant in use in the TM28 and provide the mentioned output and run times that are mentioned in the TM28 literature. I found that when I have exhausted a set and remove them from the torch, they are cool to the touch which is a good thing. This shows that the battery is not getting stressed when it gets used on turbo/6000 lumens. All in all a fantastic battery for the TM 28 or any other high power torch that requires this amount of continuous amp discharge. Not the cheapest battery, but certainly a very high performing and reliable battery.