Included: 2 x wheels, 2 x brackets, 2 x screws, 2 x washers, 2 x screw caps, 2 fixing codes, 1 x wrench; We provide a complete installation tool, so it is easy to quickly install the training wheel on your bicycle.Material: These bicycle training wheels are made of high quality plastic and rubbe. The wheel diameter is 11cm and the thickness is 2.9cm; Suitable for most 12 inch to 20 inch single-speed bikes.Thickened design: thicker design makes the wheels more wear-resistant, stable; The high-quality materials used are non-slip and noiseless. It will be safer and more stable for beginners.Safe and Stable These rear wheels provide the necessary safety and stability for the children's first bicycle attempt, and give them a good start with confidence and love for the sport.100% MONEY-BACK GUARANTEE: If you have any concern about this product, you can contact us by email and we will answer you within 24 hours. If the purchase has some quality defect, we offer a 60 days money back guarantee, you can also ask for a NEW DELIVERY for free. Note: 1. Please allow 1-3 mm error due to manual measurement and 1-3g weight error make sure you don't mind before ordering. 2. Due to the lighting of the photos and the difference of monitors, the pictures may not reflect the actual color of the real item. Please make sure you don't mind before ordering, thank you! About Shipping: 1.please pay attention to your delivery address such as: name, street, house number, doorbell/email without name, etc. is correct, or the order will not be delivered correctly. 2.All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances. 3.During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours Hope you have a pleasant shopping experience!