The Temeo Hygro Quadro Thermo-/Hygrometer offers the ability to measure temperature and humidity at four different points in and around the house. This allows for easy monitoring at a single location: Is my basement too humid? Is the nursery at a comfortable temperature? Is it too hot on the terrace? And many other customizable measurement options. The three remote sensors transmit data to the receiving station via 433 MHz radio frequency, while the receiving station also measures temperature and humidity, providing a total of four measurement results. It requires 3x AAA/LR03 batteries (for the main unit) and 6x AAA/LR03 batteries (for the remote sensors). Features: - 4 measurement results for temperature and relative humidity - 433 MHz transmission frequency - Remote sensors are splash-proof, making them suitable for outdoor use - Thermo/Hygro remote sensor - for standing or hanging.