4.2 GAL/16L LARGE TANK. Our large room humidifier is designed for rooms of up to 1000 sq.ft. and features a 4.2 GAL(16L) tank with a powerful mist output of up to 1000 ml/hr. Each tank is designed to last up to 48 hours before refilling. 4 ADJUSTABLE MIST LEVELS. 4 mist level settings to switch between Low, Medium, High and Turbo output make it easy to adjust the mist speed to your preference and provide free breathing. EASY ACCESS TO REFILLING. The top fill design makes adding water without bending. You don't even need to take out the tank to refill it, makes filling up a breeze. SMART HUMIDITY MODE. Built-in humidistat accurately detects the humidity in your room and auto adjusts to your preset humidity from 40% to 90%. 12H TIMER Sensitive touch control panel is easy to operate.