The Air Spencer CS X3 Crystal Refill Scent has an outer cassette style casing which is made from high quality plastic. Replace your old cartridge in the CS X3 Crystal case. Moreover, the case is finished with a smooth sleek finish and topped with a chrome CS-X3 emblem. The inner scent cartridge is a refillable cassette. It is easy to change out for your favorite smell. Furthermore, adjust the sliding window to intensify the smell of the fragrance. Life expectancy is estimated at about 6 weeks. Different factors rule into this estimation. Pick up your own CS X3 Crystal Refill today. Lastly, be sure to check out our other Air Freshener and other Geeky Items as well!