Usage Tips:[material] - Made of durable polyurethane material, designed to provide good grip and speed in various hardness conditions and have excellent durability [Size and Diameter] - 58 mm diameter, 32 mm width, equipped with ABEC 9 bearings and spacers, bearing inner diameter is 8 mm, bearing outer diameter is 22 mm, please make if it meets your required specifications before purchasing. The bearings and spacers are already installed on the wheels [82A Hardness, Outdoor Performance] - 82A Hardness, providing grip and soft balance, these wheels are soft enough that you 't feel every bump, but like other hybrid wheels, perfect for skating on hard or rough outdoor surfaces ] - These softer wheels are better for the outdoors because they have more "give", allowing you to bounce or small sticks, cracks and rocks. Also a decent choice for beginners on /hard surfaces, as the soft wheels make the quite slow and steady; size: 58 x 32 mm Material: PU colour: Package Contents: 8 x Skate wheel 1 x wrench 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.