Yealink EHS36 headset adapter.

"The new advanced Yealink Headset Adapter EHS36 provides the technical interface between Yealink SIP-T48S / T48G / T46S / T46G / T42S / T42G / T41S / T41P / T40G / T40P / T29G / T27G / T27P IP Phones and a compatible wireless headset. It is approved for using with wireless models made by major manufactures, including Jabra.

The unit is easy to install via a simple link from the EHS36 to the EXT phone port. Its 'plug-and-play' mode gives you direct control of your Yealink phone, with the ability to answer and hang-up calls remotely. It has been designed specifically to ensure maximum effectiveness in reception areas, call-centers and general telephone use."