... ,4-inch colour touch screen controller which shows the setting temperature ,process temperature and heating oil temperature .4, ... .6,closed system,no mist and absorption to keep the security of lab and long life of heating oil .7 ... switch, overload relays, thermal protection device and other security featuresClosed system Yes Refrigerant R-404AR-404AR404AR404AInlet DN20DN20DN20DN20Dimension 550× ...