Wheelchair Rail and Tube Compact Mount with Camera-Camcorder Round Threaded Stud Base (sku 21748)Wheelchair Rail and Tube Compact Mount with Camera Camcorder Round Threaded Stud Base. This Compact Mount features a tool less Small Tough Claw base with 1" rubber ball, a Short Double Socket Arm and a 1" rubber ball connected to a round plate with 1 4" 20 camera thread. The round plate provides extra support and stability for cameras that rest on top of it. The male 1 4" 20 threaded steel stud will connect to any standard female thread found on