"Specification: Bracket: Thickness 3mm Wheels: diameter 11.2 cm, thickness 2 cm Colour: Red Material: PVC & metal Package Includes: 2-piece exercise bikes (including components) Product Description & Product Data: 1.Prepare for people who are just starting to learn to ride a bike, until they feel a balance on the bike, and improve the child's safety and confidence. 2.With a bracket suitable for four sizes (i.e. 12.14.16.18.20 inch), the bracket can increase the support force. 3.Made of premium strong metal material. The heavy children can also use it and reduce safety problems. (Friendly Note: There is no such thing as absolute safety, so children should wear protective gear when riding bicycles and be accompanied by an adult.) 4.Cool luminous design bicycle training wheels when riding, arousing the child's interest in learning to ride a bike. 5.Easy to install. Friendly Note: 1.Please tighten the screws during installation 2. There is no such thing as absolute safety, so children should wear protective gear when riding a bike and be accompanied by an adult. " Bracket: Thickness 3mm Wheels: Diameter 11.2cm, Thickness 2cm Color: Red Material: PVC & Metal Package Includes: