16644A-B Impact Adaptor 3/4"F x 1/2"M (With Ball) | 3/4"F x 1/2"M  Impact Adaptor With Ball 

Made In Japan, Highest Quality, Most Dependable
To use your 1/2"Dr sockets on your 3/4"Dr impact tool being careful not to overload the Socket
Spring loaded ball means you do not need a Retention Pin