These are bicycle crank arm shorteners finished in black anodizing, used for reducing the pedal stroke for children or riders with shorter legs that can’t use regular length crank arms. Sold as a pair both right and left hand sides. Fits 9/16-20 threaded pedals. Also great for people with limited mobility in one or both legs, or recovering from injuries and surgeries. Made from high grade aluminum with the highest quality alloy and stainless steel fasteners. 100% USA MADE. COMPARE ours to the competition. We have the Best USA made quality and price. If your crank comes 1/8” or closer to the chain, these will NOT work for your application. SEE PHOTO. NOT RECOMMEND FOR RIDERS OVER 190 Lbs. Please leave us positive feedback. If you have a issue, contact us first. We’ll do whatever we can to resolve it. Thank you!