Carlisle Clamp-On Oar Locks are an inexpensive, easy way to secure oars to your boat. The perfect oar lock for the Carlisle aluminum Economy boat oars. Molded of stainless steel-reinforced super tough black synthetic plastic - rustproof, rattle and squeak free. Sleeved to fit either 1/2" or 5/8" sockets. Sold in pairs.