[ material]This luminous double- skate wheel is made of durable and long-lasting PU with 78A hardness, which provides performance of sliding; The skate wheel performs well on interior surfaces of wood, concrete and sports tiles, giving you a lasting grip [Sturdy & durable bearing]Using 608RS high-speed rotating bearing, sliding without noise, and fast rotating speed, and more durable. [Designed to ] Designed with an anti-stick compound reduce friction that gives a fast/, slide all the way through. [ your skate up] colorful and dazzling. The lights automatically when the wheels are spinning. So the faster you skating the brighter they Material: PU colour: green Package Contents: 8 x 6 LED luminous roller skate wheels 16 x 608 bearings 1 x roller skate wheel core Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.