- Viking telephone line powered speaker phone- Provides 2 way hands-free communication- When the Call button is pressed will come off-hook and will remain off-hook until a CPC signal is detected the programmed timeout has elapsed a busy signal is detected or the call goes silent making the unit automatically disconnect- Can be directly connectable to a CO line or analog PABX/KSU station when programmed as a ringdown circuit- One or up to four can share an existing phone line in a house or small busin