EHS (Electronic Hook Switch) cable for specific Jabra headsets for use with specific Mitel (formerly known as Aastra) telephones. Compatible with GO 64xx, Pro 9xx and Pro 9xxx series headsets, when used with Mitel 6735i / 37i / 39i / 53i / 55i / 57i / 57iCT, 6863i, 6865i, 6867i and 6869i. Manufacturer�s label indicates that this is a �Siemens DHSG cable inch which is equivalent to a Mitel EHS cable. Note: A Mitel DHSG cable is required for models 6735i / 37i / 53i / 55i / 57i / 57iCT in order to have EHS functionality, and DHSG must be enabled in the Mitel telephone settings. The Mitel DHSG cable is not required when used with Mitel 6739i, 6865i, 6867i, or 6869i telephones. No returns on opened items.