Slik Quick Release Plate 6129The Slik Quick Release Plate 6129 is a sliding plate that functions as a balance rail in several Slik tripod heads. The 6129 comes with both 1 4 20 and 3 8" mount screws that can slide along the central slot for proper placement. The slide also has a registration pin for spotting scopes and video cameras to prevent the camera or scope from rotating on the plate. The pin is spring loaded so it will retract if no registration hole is available. Two