The perfect size for your pistol or rifles when you need a fast effective up close shot with a 3 MOA. The Green Laser Bullet Drop Compensator comes with the .223 knob (other caliber knobs available separately: .25-06, .243, .308, .270 WIN, .30-06, & 7.62×39). It is backed by Osprey’s industry leading no-nonsense lifetime warranty.