Koken universal double joint impact swivel sockets, Nos. 13772-P and 14772-P, allow the user to reach into even tighter spots than one regularly can with an impact swivel. This can be accomplished by having the tool "swivel" at two different points. Simply attach any impact socket to the tool and it becomes an impact swivel. Inside the tool a mechanism allows the female drive part and body part to quickly return to a straight position. No. 13772-P works with 3/8" applications and 14772-P with 1/2" applications.