Outer Material: Synthetic Fiber Closure Type: Hook and Loop Fastener These roller shoes are very popular with both girls and boys. The flashy LEDs are built into the entire 360-degree circumference, not just part of the sole, and will get your child's spirits soaring! The underside of the shoes also lights up, giving them a high-tech feel. They are highly visible from any angle, which helps prevent accidents. The wheels are made of PU material, which has high elasticity and low abrasion, allowing for free movement. The soles of the shoes are made of TPR material, which is durable and provides high slip resistance for safety. Wheel Type: The rear wheels can be stored by pressing the button on the back, turning them into everyday sneakers, which is very practical; the front wheels can be removed with a remover, and then the sole savers can be attached to make them single-wheeled. USB Rechargeable: The LED lights can be recharged with a USB cable. 2-wheel type for beginners. A super cool gift for kids! Functionality confirmed Insole approximately 4cm Size 21cm