The RR5573-37 from Richmond Rolling Solutions is a 125mm diameter rebound rubber wheel with a maximum capacity of 100kg and has a tyre width of 30mm.The following Richmond castors use this wheel (not necessarily with the same axle diameter) R5505, S5504, S5504B, S5022.The axle diameter is 3/8 inch (9.52mm) and this wheel is available for the following alternative axle size: 5/16 inch (7.94mm).