>>3197536Well, you can find them really cheap on Amazon, but I can't say about the quality of those "good deals". Who knows what may be counterfeit.
Whatever you get, just remember they are a bitch to get off if you put them on too tight. You may need a "filter wrench" to get them off. I use one of those non-skid rubberized materials used for opening jars and preventing cutting boards from moving around on your kitchen counter top.