In this video I’m checking out the Tunenge S21X, a compact EDC flashlight the company sent out for me to review. I hadn’t heard of Tunenge before, but this one caught my eye because it’s a AA-sized light—something I don’t have as many of compared to my usual AAA carry lights. What’s cool is it’s basically dual-fuel: it ships with a 1000mAh 3.7V rechargeable lithium-ion battery, but you can also drop in a standard AA if you need to. Out of the box I didn’t love it, mainly because of the magnetic tailcap. I get why magnets can be useful, but I rarely use them on an EDC pocket light and I always have that worry about it messing with my phone or wallet. Once I started using it more, I liked it better—especially the output. On high it’s rated at 880 lumens with a claimed 200m throw, and in my backyard testing it’s definitely impressive for the size. I also go over the mode switching (high/medium/low/eco/strobe) using the single tail switch, plus momentary use. The USB-C charging port is internally waterproof (IP68), and it comes with extra colored caps and a diffuser, which is a nice bonus. I also do a quick brightness comparison between the included lithium-ion battery and a standard AA, and the AA performance honestly isn’t as bad as I expected.