This 18mm Female to 14mm Male Adapter is made to fit either a 18mm Male Bong or Rig or a 14mm Female Bong or Rig and a 18mm Male Banger or a 14mm Female Banger. Adapters change either the gender or size of your glass accessories, if you find yourself with a banger or bowl that does not fit your favorite glass rig you can surely purchase an adapter to get it to fit!