A wide variety of blades and sword styles are permitted, but all fall into one of two classes: "Light rapier" and "heavy rapier." It is not permitted for the two classes of rapier to be used against each other; participants must all be using light or heavy. Light rapiers consist of commercially manufactured foil and épée, though the hilt and guard are sometimes replaced or altered to make them more closely resemble a historical sword. Heavy rapier are full-sized replicas of historical swords, with certain differences for safety reasons: The edges and tip must be blunt, with tips covered with a cap made of rubber, leather or plastic. Heavy rapier blades must pass a minimum flexibility test to be used.