4" x 2" Swivel Caster Polyurethane on Steel Hub with Top Lock Brake 700 lbs Each (4) 4" x 2" Swivel Caster Polyurethane on Steel Hub with Top Lock Brake 700 lbs Each (4) Feature: 3/4" Roller Bearing with 1/2" ID Bushing (Manufacture will provide zerk fitting in the wheel or axle) Bearing: Roller Bearing Capacity: 700lbs each / Material: Polyurethane on Steel Hub 1 Set- (4) Swivels w/ Top Lock Brake