Viridian HS1 AR Laser Hand Stop is the world's first hand stop with a laser integrated... "Viridian Weapon Technologies' new HS1 offers increased control and faster target acquisition with a highly visible green laser that’s intuitively activated by the grip of the shooter’s support hand. The HS1 uses M-Lok mounts to make installation easy. The handstop laser is adjustable for windage and elevation.