Viking - Line Powered Off Hook Ring MW Indicator - Applications: Hearing impaired locations Call centers Telemarketing Product support groups Office cubicles CO based voice messaging Purchasing departments Sales offices - Displays "Ringing", "On-the-Phone" or "Message Waiting" on analog phone lines or PABX stations - LED visible up to 100ft - Telephone line powered - Attractive new compact package - Connects with a modular cord or screw terminals - Easy to install - Easy wall mounting with included doubleback tape