Usage Tips:1. The wheels are made of materials and have an ultra-light design to extend service life and durability, while reducing quiet vibration and wear 2. The wheel core is wrapped in fast-rolling, powerful and high-resilient PU, making riding stable and calm. 3. The wheels are equipped with our fast rolling and high precision ABEC-9 bearings 4. Suitable for most freestyle scooters with 110mm pulleys 5. Very suitable for use on wooden floors, carpets, grass, parks and paved roads. Notice: Please check whether the size is applicable before buying Material:Aluminum+pu colour:Black Package Contents: 2 x Skateboard wheels (with silver bearing) 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.