VXi 203367 OmniCord-P RJ9 Lower Cord with Universal Compatibility for Connecting VXi P-QD and Plantronics Headsets to Compatible Phones Microphone booster and adapter in one cord. Three-position compatibility switch works with most phone types. Eight-position audio booster provides transmit amplification when needed. P-type QD cord for use with VXi P-style and Plantronics quick-disconnect headsets.