Sizes include: 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16",7/8",15/16", 1", with Universal Joint. For those applications when you need a little more reach than standard depth impact sockets can provide, in a confined space that prohibits fastener access to deep impact sockets.