12mm drivers, extra bass design, in-line microphone and remote control, compatible with Sony Smart Key app, custom android control; cable length: 4 feet; frequency response: 4-24,000 Hz, 4-24,000 Hz; cable type: Y-type, flat cable. Remove the headphones: after use, remove the headphones slowly. Note: The headphones are designed to fit closely in your ears. If the headphones are pressed hard while in use or removed too fast, they may cause injury. Wearing headphones can produce diaphragm click sound. This is not a malfunction. If connected to an uncompatible smartphone, the microphone of this unit may not work, or the volume level may be low. This unit is not guaranteed to operate digital music players.