Install oars on your boat or replace old parts with these selections from Attwood Marine. Available: Clamp-On Oarlock Crafted of heavy-gauge steel with a bright zinc finish. Oarlock fastens securely to oar with one adjustable bolt, no drilling required. Oarlock Socket Accepts any oarlock with a 1/2 shank. Delrin bushing ensures silent operation. Socket constructed of durable Zamak alloy. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Oar Accessories.