High quality: The double-wheel design allows for greater caster loads than a single wheel. The tread of the furniture caster is made of high-quality rubber and won't scratch the floor at all. The structure is solid, the material is strong and durable, and the support is good. Installation: The casters are screwed on with a screw plate, screws are included, and other screws can be used if necessary. Applications: Ideal for use with your indoor and outdoor furniture on universal floors such as carpet, PVC, vinyl, tile, smooth concrete, and stone floors. Total load: The casters can support up to 40 kg per wheel, and the 4-piece set can support a total load of 160 kg, making them suitable for the flexible movement of a wide range of furniture. Easy to handle: The ball bearing is securely enclosed in a sturdy housing in a swivel plate, making it particularly easy to change direction and allowing for greater agility of movement.