Bike training wheel, also the bike stabilizer, which is a good helper compatible with beginners to reduce their fear and gradually learn to keep their bike balance. Made of steel and plastic material, much stable and safe to use. special attention to stability when building heavy training wheels, and the vertical support arm is designed to be thicker to support heavy riders. Features -Color:Black -Material:Steel and plastic -Size (wheel):10.50X10.50X2.50cm/4.13X4.13X0.98in -Size (rack):17.50X9.00X9.00cm/6.88X3.54X3.54in -Made of high strength and sturdy material, durable and safe, practical and wonderful. -Unique designed can give your child the best start with two-wheel balance and confidence. -Perfect bike accessories compatible with those who are not skilled at cycling or afraid of falling. -This is a good choice of fittings compatible with your children to learn the bike at the first time. -Easy installation, you can install this wheel on your children's bike easily and quickly. Package list: 1 x Pair of Training Wheels