Etymotic hf3. Interface type: 3.5 mm, Cable length: 1.2 m. Ear coupling: intraaural, Headphone frequency: 20 - 15000 Hz, Headphone sensitivity: 105 dB. Microphone sensitivity: 120 dB. Compatible products: - iPod touch (2nd, 3rd and 4th generation) - iPod classic - iPod nano (4th, 5th and 6th generation). Volume control: Digital