1, 3, 6, 9, and 24 (expandable with V-2925A in 24 zone increments for up to 96) zone page control units available.One-way all call to all speakers available.Volume controls and amplifiers in each speaker.No high power amplifier required.Standard CAT 3, 5, 5E twisted pair cable (typically 22 or 24 AWG) is used for speakers.Existing twisted pair house calbes / feed cables may be used without introducing crosstalk.See Multi-Path information for systems up to 360 zones.