EASY TO USE: Filter Odor and Smoke Upon Exhale. 3 Stage Activated Carbon + HEPA Filter allows you to reduce second hand smoke for roommates, family and neighbor's. REPLACEABLE CARTRIDGES: Instead of Buying a Whole New Filter, Simply Replace With a Cheap, Easy To Change Replacement Filter! Also Has Removable Mouthpiece and Cover for Easy Cleaning LONG LASTING: Can Last 350 - 500 Exhales depending on what you use it with! Way more filter life compared to other brands made of cheap plastic.