The Link2Home Zigbee Thermostatic Radiator Valve lets you manage your heating room by room from your smartphone, meaning you never have to waste money again by heating an empty room. Simply turn down or switch off the radiator via the Link2Home app and save energy. That’s not all, Link2Home radiator valves also work even if you don’t have a Link2Home Smart Thermostat. So, no matter what system you have, you can manage your heating via the Link2Home app. Requires a Link2Home Zigbee Gateway (LTHZGBEGWAY) (sold separately) for smart control. Specification: Setting Accuracy: 0.5°Setting Range: 5-35°Input Power: 2 x AA Batteries (NOT supplied)