Sony MDR-RF840RK headphone

Wireless headphone system with long battery life and 100m range -Transmission range up to 100m allowing the freedom to move about at your leisure.
-40mm driver units for deep bass response
-Hassle-free recharging by placing the headphones on the dock (headphone charged via electromagnetic induction).
-Automatic On/Off for headphones making your batteries last longer
-Rechargeable Battery will keep the music going.
-Battery playback time up to 15 hrs with rechargeable batteries or 28 hrs with Sony Alkaline batteries.
-Rotary Volume Control on Headphones.