Philips Respironics Dreamstation Cpap & BIPAP Supplies Bundle was created to assist Phillips Respironics Dreamstation CPAP & BIPAP users to replace their supplies. It includes the following: 1- 15MM Tubing. This should be replaced every 3 months.1- Water Tank (Please Note: This is the internal replacement water chamber only). This should be replaced every 6 months.1- Reusable Pollen Filter. Remember to replace your reusable filters every 90 days for optimal use while avoiding debris buildup. 6- Disposable Ultra-Fine Filters. Remember to replace your disposable CPAP filters every 30 days for optimal use.