Features: Configuration of large screen LCD display, data display clear and accurate, easy to observe. The casing is made of high quality flame retardant material PC+ABS, durable, wear resistant and high temperature resistant. High reliability single-chip computer, strong anti-interference, safe and reliable. Easy to operate with touch keys and set different working modes via buttons. Terminal wiring, relay output, and timer switch options available. Equipped with temperature calibration and anti-freezing functions. Indoor temperature controller uses microcomputer control technology to manage the start and stop of heating equipment through relay output based on the comparison between room temperature and set temperature, achieving constant indoor temperature and energy efficiency. Specification: Condition: Material: Tempered Glass, PC+ABS Working Voltage: AC200~240V, 50/60HZ Load Current: 3A (Water Heating), 16A (Electric Heating) Temperature Control Accuracy: ±0.5°C Set Temperature Range: 5°C - 35°C Temperature Limit Range: 5°C - 99°C Self-Consumption Power: <0.3W Temperature Sensor: NTC Weight: Approx. 230g / 8.1oz Size: Approx. 8.5x8.5x4cm / 3.3x3.3x1.6in How To Use: 1. Open main control panel using a 3.5mm slotted screwdriver along the inclined plane until reaching a depth of 4mm, then gently pry up to release the clip. 2. Connect the back panel to power, wire according to the wiring diagram, and secure the back panel with M4 screws. 3. Connect the wiring between the back panel and upper panel. 4. Hang the unit at a 30° angle on two hooks, press the two bottom corners firmly until the upper shell clicks into place. Installation is now complete. Package List: 1 x Thermostat 1 x Instruction Manual 2 x Screws Note: 1. Please allow 0-1 inch error due to manual measurement. Thank you for your understanding. 2. Monitors are not calibrated the same; item color displayed in photos may vary slightly from the actual product. Please refer to the physical item as the standard. 3. Hysteresis (return temperature): The factory default external sensor limit temperature (OSV) is set to 42°C, with hysteresis (dIF) set to 2. When temperature reaches 44°C, relay stops output; when temperature drops to 40°C, relay resumes output and heating continues (operation occurs when room temperature is below set temperature). 4. Please correctly select internal or external sensor mode. If the wrong mode is selected or the sensor fails (e.g., open circuit), the LCD will display "Err", and the temperature controller will stop heating until the fault is resolved. Special Hint: When installing the cable, use 1.5–2.5mm² rigid wire for water heating systems, and 2.5mm² or larger rigid wire for electric heating systems.