... Ringer HI/Low 4.lock,Ring music ,calculator Hot line headset handset phone,call center headsetSpecifications:* Backlight LCD display, date ... voice communication and the microphone (Mic) is noiseproof The headset can be worn comfortably and durably The support is convenient ... backlight lamp flashes for indication at ringing of incoming call Headset volume adjustment: 2-step toggling adjustment and 2-step ...