Description: 【Package Includes】4 pieces boat oar lock bushings. Oar stops will fit tightly, and won't fall out. The bushing will fit perfectly for the oarlock horns in your boat, protects the wood oars from being damaged. 【Size】Inside Diameter (ID) 1/2"(12mm-13mm), Outside Diameter (OD)5/8"(15mm-16mm), height is about 1 5/8"(40mm). 【Application】These oarlock bushings convert 5/8" oarlock sockets to 1/2", and minimizing friction. 【Durable Material】Nylon Oar Sleeve is made of nylon, and the outside features with thread ring texture design, wear resistant, won't slip or slide. It will much easier for rowing when the oars are firmly seated. 【Easy to use】 Nylon oarlock socket bushings, a hammer can be used to gently hammer the installation. It will snugly fit your boat, Let your row smooth and quiet. Specification: Material: Nylon Size Chart: ID: 1/2"(12mm-13mm); OD: 5/8"(15mm-16mm); Length: 4cm/1.57inch Package Includes: 4 pieces Oarlock Bushings Note: Please allow slightly errors due to manual measurement and different monitors.