CAMVATE 2 Pack 1/4"-20 Female Threaded Adapter to 3/8"-16 Male Threaded Post Thread Adapter Male 3/8"-16 to Female 1/4"-20 The adapter is made of brass. Height inc thread: 20mm (0.79") Height base only: 13mm (0.51")Diameter: 16mm (0.63") Weight: 23g