... blue or white backlightkeypad lockfunction to prevent themisusechildrenExtra sensor: 3 meters (Optional)Operation GuidePress you ... control, room sensor) / OUT (external control, floor sensor) / ALL (double temperature double control, the internal room temperature sensor, external sensor overheating protecting, ... Press the key to Set the value of External sensor hysteresis, display:dt1(setting rang:0.5 ...