- The Shockwave Lineman's 9/16" to 3/4" 12PT 2-in-1 Socket is design to increase effeciency and safety for Lineman. With an anti-rust stainless steel spring loaded design, it is the most durable 2-in-1 socket design and provides hands-free changes. The 12PT design will fit all 9/16" and 3/4" hex and sqaure hardware for increased versatility. 1/2" Sqaure Drive. A 7/16" to 1/2" impact adapter is included.