Underwater Photo Clamp for dive light Ultralight ball mount clamp  It has 30 degrees of side to side movement and measures 1 1/2" between the centers of both ball mounting holes. Uses a 1/4"-20 coarse thread bolt and works with any 1" ball. Made out of 6061 T6 aircraft-grade aluminum with Type III anodizing - Ultralight Camera Ball Mounts, Clamps, Trays and arms are available at Hollywood Divers in Los Angeles CA.   Part Number is AC-CSF-KG