This Pack Contains 2 x Top Plate Fitting Braked Castors + 2 x Rigid (Fixed) Castors | Fabricated Castors are designed using a different bearing configuration and much thicker steel to enable their higher carrying capability. Fabricated castors also benefit from a maintenance grease nipple. The wheel used has a polyurethane tyre which will offer smooth running over a compact floor. This is a very strong durable product and extremely common for all heavy duty castor applications.