This is a set of four heavy duty swivel and brake bolt-on casters with threaded M12 bolt-on and PVC wheels. It's perfect for everything from DIY to industrial applications (shops, schools, homes and hospitals). feature: Made of heavy duty steel and PVCDouble ball bearing swivel headThreaded M 12 screw fixingWheel Type: Plain Bearing, Heavy Duty PVC2 swivel wheels included, 2 swivel wheels with brake wheelsLoad Rating: 200kg/440lbs (50kg each) Ideal for everything from DIY to industrial applications (shops, schools, homes and hospitals) Specification: Item: 3 inch swivel castersQuantity: 2 x swivel wheels, 2 x swivel wheels with brake wheelsWheel diameter: 75mm/3 inchesWheel width: 20mm/0.8" Overall height: 100mm/4" (without screws) M 12 screw fixing: diameter. 12mm, length: 30mmLoad Rating: 200kg/440lbs (50kg each) Gross Weight: 1.5kg/3.3lbs Package Contents: 2 spinning wheels2 x Swivel with Brake Wheel4 M12 nuts