By providing an effective "housing" for the oar shaft Oar Stirrups will help prevent loosing your oars when they are knocked off the pin. They also make it possible to pop your oar back onto the pin with one hand, eliminating the need to stop rowing to reinstall a loose oar. Made from stiff, yet flexible, high molecular weight plastic Oar Stirrups come in pairs and include four washers. Thole Pin not included.