ITEM DESCRIPTION Durable & Heavy Duty 2pcs Rigid & 2pcs Swivel 8" Air Tire Caster Nylon Reinforced 2.25-4 Rubber Air Tires Multi-Purpose Air Tire Inflate to 36PSI Heavy Duty Zinc Plated Wheel Each Turns on Ball Bearings Wheel Size: 8" x 2-1/4" Maximum Weight Capacity: 300lb ea. Top Base Measures 4-1/2 x 4" Overall Height: 10" Bolt Spacing: 3-5/8" x 2-5/8" Grease Fitting on Base Perfect for all applications Our digital images are as accurate as possible. However, flash photography may varies.