Sonic spark plug sockets retain your spark plug when you remove it from the cylinder head. These sockets are made from Chrome Vanadium steel for strength and durability, and they are available in 3/8" and 1/2" drives in a variety of socket sizes. Each spark plug socket includes a hex profile at the top of the socket for use with a wrench. A small knurled ring at the top also aids in gripping with your fingers. Sonic Tools include a Warranty.