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