Aircare 7D6 100 is an evaporative humidifier designed for large rooms. It features a 3.5-gallon water tank that provides up to 70 hours of continuous operation, making it ideal for overnight use or in larger spaces. The humidifier also features a variable speed fan that allows you to customize the humidity level to your desired comfort. Additionally, the Aircare 7D6 100 has an automatic shut-off feature that turns the humidifier off when the water tank is empty. This helps to prevent damage to the unit and ensures that you don't have to worry about overfilling the tank.