12" Pneumatic Caster Set of 4 - 2 Swivel with Bolt-On Swivel Lock/2 Swivel with Brakes - Black Rubber Wheel - 1,800 lbs. Capacity - Service Caster Brand - Walmart.com
6" Pneumatic Caster Set of 4-2 Swivel/2 Rigid - Black Rubber Wheel - 1,200 lbs. Capacity - Service Caster Brand: 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
HAMILTON, 12 in Wheel Dia., 1250 lb, Easy-Turn Plate Caster with Pneumatic Wheels - 36T696|S-7212-PRG - Grainger