2 Wide Ring Keepers, or also called Ring Guards. Hypo-allergenic. Nickel Free. This package contains two sizes (one will fit upto a 3.5mm wide shank and one will fit upto a 6.5mm wide shank) and will keep your ring from slipping off and is much cheaper than having your ring sized professionally. My supplier states that these can adjust your ring to atleast a half a ring size if not slightly more.  These are clear non irritating plastic. Simply open the keeper at the slit and slip over ring. These are for a wider ring, such as a class ring. These also wont scratch or pinch your skin like the metal ring guards do.