Headset Buddy Agent Buddy Training Switch Adapter for RJ9 RJ10 Headsets (HM-RJ9) Dual control with 2 mute buttons. Compact for storage when not in use. Listen-in only or train/take over call Works with wired or wireless headsets or a mix Use with Agent, Plantronics, Jabra, Sennheiser and RJ9 connecting headsets Works with most telephones that have an RJ9 connection. Perfect for Call Centers.