Streamlight 88034 ProTac C4 LED AA EMS Flashlight

Features multi-function, push-button tailswitch and C4 LED technology with (1) alkaline or lithium AA battery.
Features
6000 Series machined aircraft aluminum
C4 LED, impervious to shock with 50,000 hour lifetime
Anti-roll facecap
Removable Pocket Clip
Waterproof to 1 meter for 30 minutes
Length: 3.97"
Weight: 2.3 oz.

Output
High: 50 lumens 1.5 hours (three switch gentle taps, not clicks)
Medium: 10 lumens, 19 hours (two switch gentle taps, not clicks)
Low: 3.6 lumens 36 hours