Light output on High is (672 lumens, 1hr 40min); Medium (213 lumens, 5hr 30 min); Low (27 lumens, 40hr); Strobe High-powered 33,700 hour LED 9" overall. Aerospace-grade aluminum body with military-spec Type III hard coat anodized finish Water-resistant construction. O-ring ensures seal integrity and threads are anodized for reliability. Impact resistant. Uses 3-123A Lithium batteries (included) High-powered, energy efficient lifetime LED for unmatched dependability