This is a children bike train wheel, made of rubber, metal material, and it is easy to install. What's more, your children will like this when they are train bike. And this set can be your kids' helper.These rear wheels provide the necessary safety and stability. A great for your child's first cycling lesson! Features -Color:Assorted Color -Material:Rubber, Metal -Size:11.00X11.00X3.00cm/4.32X4.32X1.18in -Made of stable and long-lasting material, which can be very firm and durable. -Made with a strengthened reinforcement design that adds unprecedented stability and safety. -When the children learn to ride a bike, balance is the first and the most important thing they need. -The overall bracket and wheels are thicker, stronger and easier to install than regular wheels. -Effectively help your child learn to ride a bike without difficulties, improving your child's safety and confidence. Package list: 2 2 x Brackets 1 x Bell