?LONG SERVICE LIFE?Because the earwax filter is a disposable design, we use the most cost-effective plastic material, but this earwax filter is is waterproof and oil-resistant, which can prolong the life of your hearing device by preventing earwax or water. ?HOW TO USE?First use screenchanger to take out old filter, then Clean the edge of the horn on the hearing aid and use the other end to stick a new filter. Finally, install a new filter and make sure it firm. ?FIT MOST HEARING AIDS?This earwax filter is designed to be mini size which can fit most hearing aids for RESOUND, PHONAK, UNITRON, WIDEX, ACOSOUND, etc. But do not fit for SIEMENS, Starkey. ?EASY TO INSTALL?Considering that most people who use hearing aid accessories are middle-aged and elderly people, our earwax filter is very easy to install, ensuring that older people can successfully install it easily. ?REGULAR REPLACEMENT?We recommend that you should change these filters regularly as they can fill up with wax and/or other non-visible debris and block the sound from your hearing amplifier. Replace the earwax filter according to the circumstances after using every six months or one year.