The JPL EHS-4 AEI-II Avaya Adapter Cord electronically connects your DECT headset base to your telephone. It enables remote operation, answer/end calls, eliminating the need for a mechanical handset lifter. For wireless headset use with various phones. Compatible with Avaya 1408, 1416, 1608, 1616, 2410, 5410, 6224D+M, 6416D+M, 9404, 9408, 9504, 9508, 9608, 9610, 9611, 9620, 9621, 9630 9640, 9641, 9650, 9670 and J179 phone models.