Construction The wheel of the caster is black plastic. The caster frame is metal with the color of antique brass. Attached to the caster frame is the grip neck socket stem which is inserted into a plastic plug which has previously been installed in the furniture item at the insertion location. (Set of 4 plastic plugs are included with these casters.) These plastic plugs facilitate the correct fit for the casters. Application These casters would be suitable in any light-duty application. Their installation will make moving the furniture item easier.