The Broan MD10TU 10-inch Universal Automatic Make-Up Air Damper with Pressure Sensor Kit is designed to provide the best technology to equalize pressure between indoors and outdoors, while providing effective ventilation for a cleaner, healthier home. Eliminate gases, smoke or particulates generated from naturally vented combustion devices like a fireplace or water heater. This is an interlocked, synchronized system that installs easily and requires only low voltage wiring to the sensor. Perfect for new construction or retrofit into an existing home.