Basic Business Set with Link (Flash) - PBX, CENTREX or SINGLE LINE COMPATIBLE, VOLTAGE MESSAGE WAITING INDICATION - Mute - LINK (FLash for call waiting, call forwarding, 3-way calling) - Redial - Hearing Aid Compatible - Visual Ringing Indicator - Matte Finish - Desk/Wall Mountable - High/Med/Low Ringer Volumes - Compact Footprint - Line Powered - Receiver Volume Control