Description: High-definition voice communication, anti-background noise Headphones are comfortable and durable. FSK / DTMF caller ID, automatic detection; 30 groups of 16-bit caller number inspection; 5 groups of 16-bit caller number access; 32-bit pre-dial and change functions; Backlight use instructions, incoming light when the backlight flashing instructions; Automatic call, manual answer, and instructions light; Microphone mute function, and instructions light; 2 files headset call volume adjustment; Ringtones volume, small adjustment and closed, and the earphone ; FLASH time 100,600ms choose to adapt to different switches; Equipped with a recording interface, can be used for training or connected with the computer sound card to record; No external power supply, can be used normally; Specification: Material: ABS material Size: 160 * 140 * 30mm Line length of 1.3 meters Scope of application: communication equipment Package Includes: 1x Headset