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