Metal Caster Wheel for Robot-20mm

From the shop's description

Metal ball caster, 1mm thick steel plate from the machine stamping, it has the capability to support 50 KG payload. The Caster is strong and lightweight with a total weight of only 120g. Large steel ball around a small ball around as much as 40 to rotate the main scroll ball much more smoothly, which make the robot walk or move at a more flexible and comfortable way. Dimensions: 55 X 30 mm Weight: 120 g Load Capacity: 50 kg