The Fenix TK28 is a high performance LED flashlight that features a dual tactical tail switch to access the four output modes and strobe. It puts out a staggering 1,500 lumens and 100 hours runtime in low mode (10 lumens). The TK28 features a durable, waterproof design intended for harsh outdoor and military use. Made from aircraft grade aluminum with a hard anodized finish, the body is knurled for grip, has a non-rolling design, and strike bezel. The TK16 uses one 21700 battery. Mode: Output / Runtime Turbo: 1500 lumens / 1 hour 25 minutes High: 350 lumens / 4 hours 40 minutes Mid: 150 lumens / 10 hours 50 minutes Low: 10 lumens / 100 hours Red: 150 lumens / 4 hours 20 minutes Green: 150 lumens / 4 hours 20 minutes