Odonil is the best air freshners from the 1st. The nice aroma is wonderful. All the flavours are the best of its own smell. But the main back drop is that it dont lasts longer. I am a regular customer for the odonil air freshners. Since many months I am observing that they are not lasting long. As they assure that it lasts for 30 days but they wont come atleast 15 days not even half of their assured tine. I only tell them that the product is cost. so we the people in will check it many tines before the item. Still we r buying this product is coz its best airpurifier. you just have to make it lasts longer as the period of time you said.