Standard 3/8"-16 Female to 1/4"-20 Male Tripod Thread Reducer Screw Adapter (Brass) Precision Made (2 Pack) Mount Adapter from 3/8 Female To 1/4 Male Inch Thread. Height inc thread: 20mm (0.79") Height base only: 13mm (0.51") Diameter: 16mm (0.63") Weight 18g (0.63oz). Package includes 2 piece of 1/4 to 3/8" male to female brass screw adapters.