Shur-Lock II is a plastic coupler designed for coupling HDPE & PVC conduit. Can also be used to couple dissimilar conduits such as HDPE to PVC, threaded or non-threaded metal conduit, or fiberglass (FRP) conduit. The coupler features stainless steel band clamps (hand tightened using a 5/16" nut driver) and locking ring. A pre-lubricated O-ring forms an air-tight seal to withstand 125 PSI on 1" - 3" sizes. Also a specialized coupler for use by electrical installers requiring ETL/UL listing.