Amazon.com: 6pcs - (M) Medium Replacement Set Earbuds Eartips Compatible with Sennheiser IE Series, CX Series, CXC Series, CXL Series, OCX Series, and MM Series in Ear Earphone Headsets : Electronics
Sennheiser Adidas CX310 Medium Earbuds (Blue)
Premium Range Replacement Medium Earbuds Tips Buds For Sennheiser CX SERIES Earphones 100% FITS (10 Pack Medium) : Amazon.co.uk: Electronics & Photo