Plantronics EHS Cable APV-66 (Avaya) Designed For: Avaya 2420, 4610, 4610SW, 4620, 4620SW, 4621SW, 4622SW, 4625SW, 4630SW, 5420, 5610, 5620; Plantronics MDA200; CS 510, 520, 540; Savi W710, W720, W730, W740, W745; Savi Office WO100, WO200, WO300, WO350 Product type: Electronic hook switch adapter Made by Plantronics