I bought my units at a local Wal-Mart store in their hardware department. But, sometimes they are out so you would probably want to call that company...their toll free # (866) 757-0012 and they will tell you where its at. OR you can just email like i did....its firstname.lastname@example.org
OR you can just buy it online at www.puricle.com ->"product info" --> Shop Online
I LOVE THIS PRODUCT... I am from Virgina where the water is yellow with black rims and Puricle was the ONLY product that works and I havent touched my toilet in 7 months!!! WHO EVER thought I would get this excited over a toilet bowl cleaner!!!! BEST INVENTION SINCE THE WHEEL!!!!