The Streamlight PolyTac HP is part of Streamlight's tactical line of LED flashlights - now with 2 brightness levels and 275 lumens in high. The PolyTac LED HP is designed for high performance. The 1.7 diameter head on the PolyTac LED HP has a deep reflector that is engineered to focus the light from the C4 LED into a powerful beam that shines up to 902 feet. The Streamlight PolyTac LED HP (High Performance) flashlight runs for up to 56 hours (in low) on two CR123 lithium batteries. Lithium batteries have a 10 year shelf life and perform better in extreme temperatures.