UNIVERSAL FIT & COMPATIBILTY: ZNS Elements In-Line filter fits most tubing for CPAP/BiPAP machines --to deliver a clean breathing experience. This filter is compatible with most machines and with 22MM & 15 MM dual radial measurements on both ends. FOR STANDARD & HEATED TUBING: The filter is suitable for use with both standard and heated tubing. Please follow the steps in the manual for instructions on how to use with heated tubing. EEFECTIVE FILTRATION: It filters out impurities from degraded foams, tiny particles, as well as bacteria and viruses. It will trap 99% of impurities, without compromising on air-pressure, so that you can get optimal air supply and breathe easy! EASY & ECONOMIC REPLACEMENT: Easy to use & replace. Great value at the price for 5 packs! DISPOSABLE FILTERS: These disposable filters can last for up to 4 weeks of use. It is recommended to replace filter at any sign of discoloration of inner lining. STERILE & NON-LATEX: Non-irritable and ensures reduction of irritants to improve user experience. SNUG FIT; NO AIR LEAKAGE:- Both connectors are designed with precision to fit snuggly to hose and or CPAP machines, and to ensure there is no loss in air pressure.