. FEATURES: Stainless Steel Construction Blue Rubber Sealed INCLUDES: Two 12mm x 18mm Blue Sealed Stainless Wheel Hub Bearings REQUIRES: Assembly onto Vehicle SPECS: Outer Diameter: 18mm (0.70") Inner Diameter: 12mm (0.47") Thickness: 4mm (0.15") COMMENTS: These are for the Inside of the Wheel Hubs, the Truck Requires Four Total of these Bearings.