PAX screens come in a pack of 3 screens for use in PAX ovens. Since they serve as a filter for your vaporizer, they need to be changed regularly (after every 25 uses). Cleaning the screens is quick and easy, just place them in a pot of boiling water and wipe them dry. Cleaning your screens will remove the build-up and give them longer life. These screens are compatible with the PAX 2 and PAX 3 vaporizers.