Included: 2 x wheels, 2 x brackets, 2 x screws, 2 x washers, 2 x screw caps, 2 fixing codes, 1 x wrench; Complete installation hardware provided for quick and easy attachment of training wheels to your bicycle. Material: Bicycle training wheels constructed from high-quality plastic and rubber. Wheel diameter measures 11 cm with a thickness of 2.9 cm; compatible with most 12-inch to 20-inch single-speed bicycles. Thickened design: Enhanced thickness improves wear resistance and stability. High-quality materials offer non-slip performance and quiet operation, providing a safer and more stable experience for beginners. Safe and stable: These rear training wheels deliver essential support and balance for children’s first attempts at riding a bicycle, promoting confidence and enjoyment in learning to ride. 100% money-back guarantee: If you have any concerns regarding product quality, a 60-day return option is available for a full refund. A replacement unit may also be requested at no additional cost.