MX W1 transmitter
Via a small sized MX W1 transmitter that must be plugged into a 3.5 audio jack you can listen to all your music from any audio or video device. It is also possible to let the transmitter send the same signal to two pairs of MX W1’s. This enables two people to listen to the same audio player at the same time.

MX W1 earbuds
The Sennheiser MX1 W1 earbuds are really comfortable. They weigh just 10 gram each and use Sennheiser’s Twist-to-fit system. The MX W1 earbuds have their own internal batteries and can be fully recharged up to three times on the mobile carry case.