Inova T3TMB-HB T3 Lithium Powered LED Flashlight Light output on High is 264 lumens and on Low is 21 lumens Run time on High is 4 hours 20 minutes and on Low is 48 hours Effective range is up to 518 -Feet or 158 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