100,000 hour lifetime, high intensity Light Emitting Diode (LED). Provides 12,000 millicandelas of light. Includes (3) AAAA alkaline bateries and pocket clip. Waterproof. 6000 series tempered aircraft aluminum with anodized finish; non slip knurled grip. Over 10 hours run time on fresh batteries. 2 mode switch - constant on and momentary blink.