The Novoflex QPL-Video Arca-Type Quick Release Plate for Q-Base System is a Q=Plate series quick release plate that fits any Arca-type quick release system (except the Arca Swiss Flip-Lock). This plate comes with a choice of both 1/4"-20 and 3/8" camera mounting screws, and features a video location pin that prevents the camera from twisting when in vertical position. Note: They are not recommended for use in the Arca-Swiss Flip-Lock quick release clam