This is a set of replacement lip pieces that can be used with the SOLID VALVE System for the VOLCANO Vaporizer. The lip piece is the plastic component on the end of the mouthpiece and is a commonly lost item. If you have lost your lip piece, this set will get your mouthpiece functioning properly again. You may also want to keep extra lip pieces on hand when sharing your Volcano, for Hygenic reasons. Before purchasing this, please ensure that your unit has the SOLID VALVE System. These will not fit if your unit has the EASY VALVE System.