This is a high quality air freshner machine. It comes with a refill (250ml -life scents fragrance) and two pcs of non- rechargeable alkaline batteries. The battery can be changed to any type provided they are the same size.This air freshner last for about three months before refilling. You can change to another fragrance anytime you want to refill. Each time you travel pls remove the battery so it won't be wasting. Caution: pls keep out of trash of reach of children.