8" x 1-5/8" Mold-On Rubber Aluminum Wheel Swivel Caster - 400 lbs. Capacity8" x 1 5 8" Mold On Rubber tread Aluminum Wheel 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: Ball Bearing Rig: Stamp formed swivel caster with bright finish and swivel dust cap, 2 3 8" x 3 5 8" mounting plate Capacity: 400 Lbs. Color: Black and Silver