ABEC-9 rating: the higher the rating the better the precision and efficiency and our rating is at the top of the spectrum. Suit for: skateboards, longboards, and roller skates, being compatible with any size wheel. also suitable for spinner toys. Sealing: each ball bearing has two low friction blue single lip rubber seals. All Weathers: these bearings are waterproof, dust and dirt proof and will keep your wheels rolling. Universal Size: 608rs classification with a 8mm core diameter. 22mm outer diameter with a 7mm width. Specification: Diameter: 22mm / 0.86inch Hole Diameter: 8mm / 0.31inch Thickness: 7mm / 0.27inch Package Includes: 16 Pieces Skate Bearings Note: Please allow 1-3mm measuring deviation due to manual measurement. Due to the different monitor and light effect,the actual color of the item might be slightly different from the color showed on the pictures.Thank you!