This is a set of 4 screws for Rimowa multi-wheel suitcases. They can be attached and detached using a Torx T20 screwdriver (sometimes included with the suitcase; a T15 can also be used in my experience). The length is 25mm, and they are generally compatible with wheels with a diameter of 46mm, but please check the screws you have just in case. The material is stainless steel, which is more resistant to rust than iron. Caster Tire