you can also get them through Kynoch, i had to e-mail them, and they got right back to me, i placed my order over the e-mail along with a half a dozen foam wads. there snap caps are stainless.
i ordereed them because i could find any 500NE anywhere else, the A Zoom snap caps are nice also and i have a pair of 470's, but i could find them in 500 or larger.