CTA Tools A164 Thin-Wall Impact Flip Socket - 19-Millimeters by 21-Millimeters is designed to fit into tight spaces where normal sockets can't and servicing recessed wheel nuts. The socket features a 1/2-Inch drive in the center that allows the socket to "flip” from one size to another. The overall length of this socket is 3-Inch (76-millimeters). Heavy-duty construction allows for strength and durability. Whether tuning up your ‘68 Corvette or changing the oil on a John Deere tractor, CTA can supply you with the tools needed to do the job. California Prop 65 - Warning, This product contains chemicals known to the State of California to cause cancer, birth defects or other reproductive harm.