This automatic aeroso dispenser can spray out fragrance automaticly.And have 3 work status:DAY(works when there is light,stops automaticly when there is dark);NIGHT(works when there is dark,stops automaticly when there is light);21H(works round the hour).3 interval for you to choose:10 minus(sprays every 10 minutes);15 minus(sprays every 15 minutes);20 minus(sprays every 20 minutes).