BlueSpot Tools Impact Adaptors are manufactured from chrome vanadium for increased durability with a blackened phosphate coating which offers protection against corrosion damage. The spring ball socket retainer ensures a secure fit. Sizes: 3/4in F x 1/2in M, 1/2in F x 3/8in M and 3/8in F x 1/4in M. Ref: UTTK12822