6 Inch Pneumatic Caster Set: Amazon.com: Industrial & Scientific
CasterHQ 10" x 3.5" Swivel of 4 Set Pneumatic Caster - 4 PLY - 350 LBS PER 1400 LBS PER Set Capacity - Air Filled - Commercial/Industrial Application 10 inch x 3.5 inch Shock Absorption: Amazon.com: Industrial & Scientific
6" Pneumatic Caster Set of 4 - 2 Swivel with Brakes/2 Rigid - Black Rubber Wheel - 1,200 lbs. Capacity - Service Caster Brand - Walmart.com
8 in. HD Pneumatic Wheel 0.5 in. Hex Bore - AndyMark, Inc
Shepherd 8 in. Black Rubber and Steel Pneumatic Swivel Plate Caster with 220 lb. Load Rating 9794 - The Home Depot