With a peak output of 1500 lumens, the T21 Tactical LED Flashlight from Acebeam is suited for search and rescue, law enforcement, security, industrial, recreational, and emergency preparedness use. This substantial torch offers five brightness levels plus a strobe for self-defense or signaling. It can be used in two configurations—run it on one 18650 battery or two CR123As, with a maximum brightness level of 1000 lumens, or attach the included extender and use two 18650s for the 1500-lumen output. The maximum runtime for the 0.5-lumen ultra-low setting is an impressive 1200 hours. A side-mounted push button turns the light on and off and cycles through the brightness levels and the strobe. The aluminum housing is IPX8-rated, submersible to 6.6', and impact resistant to 3.9'. The bezel is threaded to accept color filters for specialty work, and the glass lens of the light bears an anti-reflective coating for maximum light transmission.