Quick disconnect cable required for Telecom headsets to enable direct connection to most standard telephone system handsets. The BL-10+P Geni lead is perfect for offices where there is more than one type of phone system in use - the BL-10+P Geni lead comes with a compatibility switch which allows you to adjust to the correct type of handset quickly, rather than having to have two separate leads for your phones. Simple 8-position slide adjustment - no need for a user manual. Simply slide the switch until a dial tone is heard. Standard RJ11 connector connects to virtually all telephones using a standard modular plug. Standard Plantronics compatible quick disconnect plug to headset. Works with any JPL or Plantronics headset equipped with quick disconnect. Built-in low-current microphone amplifier enables perfect operation with telephones that require extra signal gain.