High-quality material: These training wheels are made of rubber material and a metal bracket, with a diameter of 11 cm and a thickness of 2 cm, suitable for most 12-20 inch single-speed bicycles. They provide extra stability and safety to the bicycle, ensuring that children can cycle safely and stably for a long time; they are a reliable support for beginners. Safety and stability: These training wheels light up while cycling, which increases safety at night or in dark environments. They are designed for beginners and have reinforcement clamps added to the metal bracket to form a robust triangular design to maintain balance and provide the necessary safety and stability for children to learn to cycle with confidence. Easy installation: These training wheels are easy to install with a complete accessory kit that includes 2 vertical support arms, 2 wheels, and 2 nuts. All parts are easy to handle, ensuring quick and easy installation so that children can cycle safely. Universal adjustment: These training wheels are suitable for 12-20 inch single-speed bicycles with a horizontal chainstay design, not for a vertical chainstay design. The adjustable support arms allow you to easily adjust the wheel position for optimal fit and stability, providing your child with better support while cycling. Low noise: The specially designed tire structure and high-quality bearings on these training wheels significantly reduce noise during cycling, ensuring the safety and stability of your child's bike ride, while also making the ride quieter and smoother. The environmentally friendly materials are durable and reusable, increasing the product's safety and comfort.