Sennheiser 506037 is a CEHS-AV 05 cable for electronic hook switch. It can be used with Avaya IP desk phones and Sennheiser wireless office headsets such as DW Office, DW Pro 1, and DW Pro 2. This cable allows users to remotely answer and end calls, as well as manage calls efficiently and flexibly. It also provides call control towards the phone without using a mechanical handset lifter. The CEHS-AV 05 is easy to set up and compatible with Avaya system software version 1.8 or higher.