I have this air freshening system and I really like it! The refills last a pretty long time and they have some really great fragrances–my favorite is Paradise Breeze-Tahiti!  I was so excited to find that I can get these free, after submitting a mail in rebate, at Rite Aid.

Renuzit Crystal Elements Air Freshening Crystals Refill, 18 oz $5.49, Regular Price
Submit FREE Renuzit Crystal Elements Refill, up to $5.60  Mail in Rebate
Final Price: Free 

Thanks, Hip2Save