Albion R4 Large Locking Steel Swivel 4" x 2" Rolling Caster Wheels (4)
6" Polyurethane Rigid Caster -310PY06501R - Caster Central
Albion 62PD06201SFBB HD Swivel Caster with Face Brake, 6" Polyurethane on Aluminum Wheel, Roller Bearing, 2" Crown Tread Width, 6-1/4" L x 4-1/2" W Plate, 1230 lb. Capacity: Amazon.com: Industrial & Scientific