This is a fabulous product. I filled it up and away it went. Right away I felt the air get a bit cooler. Allergies are a killer where I live and this opened up my nose right away. Headache is gone. I can't say enough about it. The size is great will fit a large room. Different settings are great sleep mode, auto, low, medium, high and it can be used as a smart device. In the back there's a small compartment to add a few drops of oil to the pad and the water will run through it. Don't add any drops of oil anywhere else or you will ruin the machine. It's durable. Great quality.