12 Ball Bearing Casters: The package contains 12 metal conveyor bearings, 3 x 3 x 1.5 cm / 1.2 x 1.2 x 0.6 inches, unit load 15 kg, permissible load 25 kg. The ball transfer casters rotate flexibly and the ball part in the middle can rotate 360 degrees, this means you can transfer goods in any direction. Galvanized Carbon Steel Material: The ball caster is made of heavy-duty galvanized carbon steel, which is harder than stainless steel rollers, has a higher load capacity and has a longer service life. Our unit ball bearings can arbitrarily set the distribution density of universal balls according to different load requirements and can be matched at will, which is more convenient. Quiet transportation: The heavy-duty ball caster is precisely ground and polished, the surface is very smooth, the rolling speed is fast, the stability is good, and it is wear-resistant, so it runs smoothly and quietly. In the transportation process, this can greatly improve work efficiency and save working