Wow, runs up to 18 hours!

This is the largest diffuser I have owed and love how it lasts all day.  The diffuser has a beautiful light wood grain and a small amount of colorful lights.  It holds up to 530ml and will work for 2 hour, 4 hours, 8 hours or ON continuous until the water runs out. You also have the option to have the mist on high or low depending on how long you need it to last. I like to add essential oil to keep a fresh fragrance through-out my house. I usually add about 4-5 drops of essential oil in the water. I prefer peppermint in the winter and lavendar at night. I have been very happy to have this diffuser since it lasts very long.