Contains 4 swivel casters with a total load capacity of 60 kg. The diameter of each caster is 38 mm and the screw size is M8 x 20 mm. Our casters are made of high-quality TPE material with good abrasion resistance. The wheel core is made of polypropylene, which is highly thermoplastic and corrosion resistant. The outer wheel is made of synthetic rubber, which is wear-resistant and has a good anti-slip effect. These casters run quietly and smoothly, without scratching the floor. They are very suitable for use in furniture such as coffee tables, children's beds and cabinets.