Sony Wireless Stereo Headset Silver MDR-1ABT / S Type: headband, Stereo / Mono: Stereo, structure: sealed, noise-canceling: non-compliant Surround: non-compliant, wireless: Bluetooth, Interface: mini plug (3-pole) / Bluetooth Maximum input: 100mW. Frequency band (L): 4Hz, frequency band (H): 100000Hz "If the communication condition is poor, the BLUETOOTH device may react incorrectly to the operation on the headset." "The available functions may vary depending on the BLUETOOTH device. When you operate as illustrated above, it may operate differently or may not work at all."