Rock Steady SS Stainless Steel 1/4" to 3/8" Bushing Adapter/Tripod 50mm Diameter Desmond Desmond Brand. 100% metal. Stainless Steel Super strong Use to convert a 1/4"-20 threaded post to a 3/8"-16 or to convert a 3/8"-16 thread socket to a 1/4"-20. 3/8" metal male thread and 1/4" metal female socket.