Vodavi Starplus STS SP-3515-71 Speaker Display Phone (Charcoal/Refurbished)Key Features: PBX Centrex Compatibility Supports full or fractional T1 Phones are CTI adaptable ADP Additional Device Port on every phone for fax or modem connection Standard 2. 5 mm Headset Jack on every phone Voice Mail does not reduce System Capacity UCD & LCR Capability Easy to Configure, Install & Program One phone model loaded with features Soft keys below display enable quick access to system features Name & number display Caller ID is standard