Create a networked zoning system when combined with up to three T8635L Microelectronic communicating programmable thermostats and a W8635A,B equipment interface module. Networked zoning enables these features: — Time synchronization — Shared-filter indication — Vacation hold in all zones — System switch setting automatically changes in all zones — Individual fan control in each zone — A single network can use up to nine T8635L Thermostats and three W8703 damper interface modules to control nine zones.