Made of high-quality materials. oarlock socket bushings, a hammer can be used to gently hammer the installation. Bushings convert 5/8 inch oarlock sockets to 1/2 inch, and minimizing metal-on-metal friction. It is made of , the outside of the oarlock bushing has many thread ring, provides long wear, won't slip or slide. It will much easier to row when the oars are firmly seated.<br><br>Colour:Black Material:plastic Note: Installation guide not included, we strongly recommend you seek professional installation. Please check as much as possible to make sure the item is what you need. Due to different batches, there may be differences in product appearance and printed text, which will not affect use<br><br>Package Contents: 4 * Oar Lock Socket Insert<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.