Operation guide for temperature. & Humidity meter - large LCD screen - high accuracy and stability - multifunctional - low power consumption. Customization - temperature range. Indoor unit: -10°C ~ +50°C (+14°F ~ +122°F). Outdoor: -50°C ~ +70°C (-58°F ~ +158°F) (if the meter has an external temperature transmitter). - Humidity range: indoor 20% ~ 99% relative humidity (when humidity is 20% relative humidity, display 10% relative humidity directly). - Power source: 1.5V (AAA size) × 1. Tasks - display indoor/outdoor temperature, display indoor humidity - temperature unit C / F adjustable - memory of maximum/minimum temperature and humidity values - two time display modes: 12-hour / 24-hour - clock and date display function, automatic switching every 5 seconds between clock and date - hourly alarm function - daily alarm function - install external temperature sensor, automatically alternates display of indoor and outdoor temperature every 5 seconds (only for typical models).