A dispenser for a volatile material may be a cover that may be selectively attached to a base to form an internal cavity between them. A method is described for providing a visual indication when an item, such as the cover, needs to be replaced. The cover has a first initial size condition. The volatile material is permitted to evaporate from the cover into the air. The cover is permitted to shrink to a second size condition to provide a visual indication that the cover needs to be replaced.