Designed for impact or hand tool use. Magnetic retention device keeps the adapter attached to the socket. Adapters can be stacked if additional drive reduction is needed. Sleeve type - low profile. Lifetime Warranty This reducing adapter set helps to reduce larger drive sizes down for use on smaller drive tools. The set contains 938RA 1/4" Female x 3/8" Male, 1138RA 3/8" Female x 1/2" Male, and 2238RA 1/2" Female x 3/4" Male.