Polycom Soundpoint Replacement Power Supply 24vDC 500mA that works on the following business telephones.Polycom, SoundPoint, VoIP, IP, IP300, 300, IP320, 320, IP321, 321, IP330, 330, IP331, 331, IP335, 335, IP430, 430, IP500, 500, IP550, 550, IP560, 560, IP600, 600, IP601, 601, IP650, 650, Phone Power Supply, Telephone Power Adapter, Black