3 1/2" overall. Machined black aluminum housing with black stainless pocket clip. CREE XPG LED. Three modes: high, low, and strobe. Accepts one Lithium CR123 battery or one AA battery (included). Using Lithium CR123 battery - high: up to 175 lumen output with 2 hour runtime; low: up to 30 lumen output with 9 hour runtime. Using AA battery - high: up to 150 lumen output with 45 minute runtime; low: up to 30 lumen output with 4.5 hour runtime.