Greenlee Conduit pistons are used with blower or vacuum power fishing systems to pioneer the line through the conduit run. Their flexible foam body forms an air tight seal against the interior of the conduit. End disks are color coded with embossed size markings to help the user easily identify the correct size piston. The center rod is made of durable steel and has loops on either end. Conduit rats are available for all types and sizes of conduit - 1/2" through 6".