SureFire KE2-A LED WeaponLight Conversion Head Virtually indestructible LED and TIR lens produce brilliant 500-lumen beam optimized for close- to medium range applications Construction-High-strength aerospace aluminum with Mil-Spec anodizing; coated, tempered window Weatherproof-O-ring and gasket sealed TIR lens for close- to medium-range applications 1.125" bezel diameter