AEROKAT Cat Asthma Aerosol Chamber &ndash; Easy to Use Inhaler Spacer &ndash; Asthma Relief for Cats &ndash; Asthma Spacer Compatible with Metered Dose Inhalers (MDI) for Allergies & Cat Wheezing &ndash; Fits All Breeds The AEROKAT* Feline Aerosol Chamber allows your cat to breathe normally while inhaling medication Low-resistance valve only releases medication as cats inhale; FLOW-VU* indicator monitors inhalation Works with all metered dose inhalers prescribed by veterinarians for cats' wheezing, asthma, etc. Delivers medications directly to the lungs, requiring a lower dose of drugs with fewer side effects Includes two face masks: a small mask for cats weighing 10lbs or less, a large mask for cats &gt; 10lbs