Combination set: 2x wheels 2x brackets 2x screws 2 x washers 2x nuts 1 x Wrench We provide a complete installation tool that allows you to easily install the auxiliary wheel on your bike High Quality: The children's bicycle stabilizers are made of high quality ABS wheels and solid metal The sturdy stand increases stability and safety and the wheels are non-slip and wear-resistant Safety and Stability: Heavy-duty auxiliary wheels provide safety and stability for kids trying out bikes for the first time Let beginners keep their balance while cycling improve children's confidence make them full of confidence and love sports and enjoy the fun of cycling Flashing wheel design: This training wheel is a flashing wheel with an integrated magnetic core which will glow when spinning They are non-slip and quiet and the flash function makes kids more interested in night driving Universal size: our bike stabilizer wheels are suitable for children's bikes from 12 years old 14 16 18 and 20 inches to meet the needs of growing children and learning to ride Note Please check if these wheels are compatible with your bike Cannot be installed on bikes with derailleurs