5" x 2" Mold-On Aluminum Wheel w/ Ball Bearing - 500 lbs. Capacity5" x 2" Mold On Aluminum Wheel Ball with Ball Bearing The mold on rubber aluminum wheel is a lightweight alternative to the traditional cast iron core, providing the same load capacity with a cushioned tread and an attractive look. Tread: Rubber Vulcanized To Core Core: Aluminum Core Bearing: 1 2" Annular Ball Bearing Capacity: 500 Lbs. Color: Gray and Non Marking Durometer: Shore A 80 (+ 5) Temperature Range: 40 F to 160 F Load Capacity 500 Lbs.