Description:?- Viking Ring Generator- Reshapes Troublesome Distorted Ringing Signals- Boosts Ringing Power Of Analog Isdn Terminal Adapter Ports- Use With Viking??S Doorboxes To Increase The Number Of Phones They Can Ring- Boost Ring Power On Telephone Lines Or Analog Pabx/Ksu Stations That Are Weak Or Fail - True Sine Wave Ring Signal Output- Boosts Ring To 4 Ren- Caller Id Compatible- Easy Installation- Compatible With Distinctive Ringing Services- Will Not Affect Normal Line Operation- Reshapes Troublesome Square Wave Ringing- Not Compatible With Pulse Dialing Vkrg4