The T.M.P.R. SYSTEM is a modular system of purpose-specific optics that can be used individually or in combination to create the ultimate sight for any situation. Each T.M.P.R. System component has its own battery. When connected to a T.M.P.R. prism sight, they can be powered by the prism sights high-capacity CR123 battery. The red laser is compatible with the T.M.P.R. Prism Sight allowing for it to share its power instead of relying on battery power. Perfect for low-light, fast-action tactical shooting and home defense.