The Beamshot ST1 Tailcap Switch is part of the latest generation of Military-grade power button options designed to let you power up your tactical sights quickly, silently and easily. The Beamshot ST1 Power Switch is made to work with the Beamshot GB800M Laser Sight, providing constant on-off power settings. Simply screw in the pushbutton switch onto the rear of the laser sight, for easy one-finger ambidextrous on-off capabilities. This tailcap power switch is identical to the one that comes with the Beamshot GB800M Kit and can serve as an upgrade or replacement part. Whether you are a left- or right-handed shooter, you'll want to upgrade your Beams hot Laser Sight with the Beams hot ST1 Tailcap Switch for easier and faster activation. Beams hot ST1: Tactical Military & Law Enforcement-grade Tailcap Switch works with all Beamshot laser sight including BS1000S, BS 1000U, GB800M, GB3000, GB 1000 and GB2000.