I went to every store in Vegas and was told over and over "good luck!", meaning that no one has them. Asked around and found out that the minimum purchase is some ridiculous amount that is not worth the effort. I am so pleased that I got these, I change mine out all the time, it seems this is the first clog that happens and the easiest way to clean it, is to replace it! I leave the dirty ones in Rubbing Alcohol for a day or so and then they are clean and ready to reuse.