Amazon.com: Sennheiser Consumer Audio CX Plus True Wireless Earbuds - Bluetooth In-Ear Headphones for Music and Calls with Active Noise Cancellation, Customizable Touch Controls, IPX4 and 24-hour Battery Life
Best Buy: Sennheiser CX 400BT True Wireless Earbud Headphones White CX400TW1 White
Amazon.com: Sennheiser CX400-II-B In-Ear Headphone with Dynamic Speaker System and Integrated Vol Controls (Discontinued by Manufacturer) : Electronics