Walgreens has these too. I lined it with a sheet of heavy aluminum as an additional shield for my new RFID PP.* If you only slip one PP cover into the longer of the two plastic holders on the clear cover, it holds very well, yet is instant off if you encounter the TSA Blacklight Inspector who wants to see its naked blue skin. Surprisingly little UV glows in my new PP, I'm a little disappointed. . .

*Snicker if you want, but since covering my PP with a Faraday Shield, I have not seen a single UN Black Invisible Helicopter outside my window, so it works.