Enhance your Hydro-X system with this versatile 3-in-1 sensor, designed to monitor temperature, humidity, and light levels. Featuring a built-in photocell for automatic day/night mode detection and an 8 ft RJ12 cable for easy connectivity, this sensor ensures seamless integration. Its plug-and-play functionality makes installation a breeze. Please note, this is a replacement or spare part; the main controller already includes a sensor.