These are the new MX W1 wireless headphones from Sennheiser, being launched at the 2008 CES show.
Thanks to technology from US company Kleer, the new 'phones claim improved sound quality and greatly reduced power consumption compared to Bluetooth devices, enabling the headphones to be run on tiny button cells, rechargeable on the move from a portable battery pack.
The new Sennheisers comprise separate earpieces, with no cable between then, linked wirelessly to a matchbox-sized transmitter with a band to attach it to portable music players
The whole system fits in a small travel case with a conventional rechargeable battery inside, and this can recharge the earpieces and transmitter on the move.
It's claimed that the Kleer Audio LP technology used, which delivers CD quality on the 2.4GHZ band, has as little as a tenth of the power consumption of Bluetooth rivals, and it can also be used to transmit to extra headsets, so two listeners can enjoy the same music if required.
The earpieces themselves feature new drive units developed at Sennheiser's technology centre in Ireland, and the company's 'twist to fit' system to ensure they stay in place in the user's ears.
Kleer expects its transmission technology to be built into portable devices in the near future, removing the need for the separate transmitter unit.
The Sennheiser MX W1 headphones will go on sale in May.