8 Medium (M) Ergonomic Replacement Set Earbuds Eartips for Sennheiser IE Series, CX Series, CXC Series, CXL Series, OCX Series, and MM Series In Ear Earphone Headsets 8 Medium (M) Ergonomic Replacement Set Earbuds Eartips for Sennheiser IE Series, CX Series, CXC Series, CXL Series, OCX Series, and MM Series In Ear Earphone Headsets 8pcs (M) Medium Ergonomic Replacement Ear Adapters Ear tips. Perfect fit and comfort for your ears, left and right. Great replacement for any damaged, scratched or defective Earbuds Ear tips. You can also use these to provide better hygiene - when you change often. With one hand hold the ear tip and the other, the In-Ear Earphone Driver. Place the Driver of the Earphone in the edge of the ear tip canal. Apply pressure and with a circular motion, twist with one hand clockwise and with the other the opposite direction  until the ear tip has fully covered the Driver of the Earphone. Once you have put them on properly, they will stay on securely.