This is a RF wireless room thermostat control heating system in each single room. Build-in sensors in your  wireless room thermostat detects when the temperature falls to a chosen level and then feedback to the heating system to turn on.  Item No.: WT-20 Programmability: 7days programmable Mode: Manual Mode, Away Mode, PRG Mode  Color:  White  Backlight: White Material:  ABS+PC Packing : Netural White Box, OEM acceptable Other function: Child lock, Open window detection, Frost protection, Temp. calibration  Optional: Opentherm protocol, WiFi optional, Zigbee optional Cetificate: CE, ROHS, UKCA, REACH, RED