Sound by KEF. Design by Ross Lovegrove. KEF’s Mu3 Noise Cancelling True Wireless Earphones are engineered to deliver pure, accurate sound everywhere. Designed in collaboration with visionary designer Ross Lovegrove, the Mu3s deliver exceptional sound on the move while being comfortable and elegant. DISCOVER MORE Limited Time Free Shipping. Act Now. Due to high demand, please allow 5-7 days from dispatch, for the delivery of your Mu3 order. Exact delivery times may vary depending on the Covid-19 situation of each country.