Inova T1TMB-HB T1 Lithium Powered LED Flashlight Light output on High is 241 lumens and on Low is 20 lumens Run time on High is 4 hours and on Low is 47 hours Effective range is up to 370 -Feet or 113 m Mineral Glass optical window has double-sided AR-coating and Teflon seal to withstand environmental pressures High-powered energy efficient 50,000 hour LED