Williams 39005 1-Inch Drive Impact Socket Adapter, 3/4"M X 1"F Adapter Specially heat treated for impact use to provide long life, safety, and durability Suitable for use with pneumatic and electric impact wrenches Black industrial finish Meets or exceeds Fed. Spec: ANSI B107.2 This impact socket adapter is used to reduce a 1-Inch drive tool to 3/4-Inch drive tool