Material: 7 ceramic beads in the GCR15 steel bearing ring Suitable for: Longboard, Inline Skates, Skateboard, Scooters, Skateboard, double-row wheels and more High quality choice: Smoother, faster and less noise than ordinary stainless steel ball bearing, especially corrosion resistance Size: 8mm x 22mm x 7mm ( Inner x Outer x Thickness) Package Included: 4 x Hybrid Black Ceramic Bearings Experience smooth and fast rides with our Z-First High Speed 608RS Hybrid Black Ceramic Bearings. Crafted with 7 ceramic beads in a GCR15 steel bearing ring, these bearings are designed to outperform ordinary stainless steel ball bearings, providing less noise and exceptional corrosion resistance. Ideal for longboards, inline skates, skateboards, scooters, and more, these bearings measure 8mm in bore diameter, 22mm in outside diameter, and 7mm in thickness. Each pack includes 4 bearings, ensuring you're well-equipped for your adventures. Upgrade your ride today with our high-quality, durable, and efficient ceramic bearings.