4 Inch Heavy Duty Rubber Mute Spring Loaded Gate Door Wheel Caster 100kg Load Capacity Home Gate Door Roller Furniture Hardware - Furniture Casters - AliExpress
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Shepherd 4 in. Black Hard Rubber and Steel Swivel Gate Caster with Adjustable Spring Bracket and 125 lbs. Load Rating (2-Pack) 9785-2 - The Home Depot