... water circulation Makes the whole split system work efficiently. Working Station KitsInclude:Circulation pump, expansion tank 5L~8L, controller, manometer, ... AC220V, 50HZ(optional)2. Consuming power: <3W3. temperature test range: 0~99 degree.4. water temperature controlling attainability precision: ±1 degree ... W.6. electric heater power: 1500W.7. creepage currency: ≤10mA/0.1s Working Station Kits