The lip piece for Storz & Bickel Vaporizers in intended for hygienic single use. Each piece is equipped with a check valve to reduce contamination of the cooling unit and keep it sanitary. The valve works by permitting air travel in only one direction (into your mouth), while keeping saliva and other particles from travelling through the mouth piece. This set of lip pieces works with the Mighty, Crafty, Volcano, and Plenty Vaporizers. This product helps you maintain cleanliness and good hygiene. Each set contains 30 single-use Lip Pieces.