This BL-02+P U10 RJ-9, Cisco and Vista Equivalent Amplifier / PLX QD Cable enables direct connection to most standard telephone system handsets. It allows you to move away from your desk during a call without removing the headset. It also lets you put a call on hold, by simply disconnecting the headset from the QD during a call. Its an ideal solution for intensive telephone users such as in customer care centers and technical support services.