Carlisle Clamp-On Oar Locks Carlisle locks are molded of stainless steel and reinforced with super-tough black synthetic plastic for long-lasting durability. Rustproof, rattle-proof, and squeak-free, the oar locks do the job quietly without attracting attention. The locks are ideally suited to Carlisle Economy aluminum all-purpose boat oars. Ready to deliver years of worry-free service, Carlisle products provide exceptional strength and reliability at a great value. Sleeved to fit either 1/2-inch or 5/8-inch sockets; sold in pairs. Durable stainless-steel reinforced plastic construction is rustproof, rattle and squeak free Sleeved to fit either 1/2" or 3/8" oar sockets Perfect fit to Carlisle Aluminum Economy oars