Standard 1/4"-20 Female to 3/8"-16 Male Threaded Reducer Screw Adapter (Brass) Precision Made (2 Pack) Standard 1/4"-16 Female to 3/8"-20 Male Threaded Screw- Brass. Sturdy construction and precision made. Height inc thread (approx): 20mm (0.79") Height base (approx): 13mm (0.51") Diameter: 16mm (0.63") Weight 22g (0.78oz). Package includes 2 piece of brass adapters.