1Block Particles: The filter kit effectively blocks fine particles and large particles, thus protecting the machine, providing clean air and ensuring the health of the elderly. 2Perfect Fitment: Suitable for Philips Respironics DreamSation 2 breathing machine, wonderful replacement for the old or broken one, easy to install. 3Regular Cleaning: The reusable filter can be cleaned every two weeks to maintain a clean and hygienic breathing machine, extends service life of the machine. 4Use Time: The sheet filter is for disposable use, one or two pieces a month; and the box filter is one piece for every three months, and it is used repeatedly after cleaning. 5Multiple Applicable Place: Lightweight and in small size, easy to store and carry, can be easily put into your bag, suitable for home, hospital, health center, etc.