This Neb Kit Is Disposable It Would Need To Be Replaced Every Two To Three Weeks. The Timeframes Do Depend On The Frequency Of Usage. General Rule Of Thumb Is If You're Noticing That The Medication Isn't Nebulizing As Quickly Or As Much It's Time To Replace The Neb Kit. Nebulizer Mouthpiece Universal T 7 Foot Kink-resistant Tubing Anti-spill T Design Leak-proof And Secure Seal With Simple 1/4 Turn Assembly Design Very Low Dead Volume (07cc) High Medication Bowl Capacity (13cc) Graduated Volume (cc) Markings On Bowl Nebulizes In Upright Positions Or Angles Up To 45 Degrees Latex Free Prescription Needed