The DigiStat is a remote wall-mounted thermostat that can control the Amana brand DigiSmart PTAC from anywhere in the room. It is powered by 4 AA batteries that are included in the kit.The DigiStat communicates on a two-way RF encrypted signal. Settings can be changed either at the DigiStat or on the PTAC at the DigiStat touch-pad. Settings are automatically relayed to the other device within moments.A DigiTenna (DT01A) is required for the DigiStat to communicate with the DigiSmart PTAC.