The TCM-550XL Compact Tactical Weapon-Mounted Light uses a super-bright LED rated at 550 lumens working in conjunction with a precision-engineered total internal reflection (TIR) lens to create a bright white beam of light rated at 136 meters. This weapon light features completely ambidextrous and intuitive rear-facing toggle switches on each side of the light to operate the momentary-on and constant-on lighting modes