Check out this thread: http://www.toyota-4runner.org/showthread.php?s=&threadid=8592&highlight=vsv
My dealer referred to it as a "Purge Vacuum Switching Valve".
A Google search for "locking valve stem caps" came up with these: http://www.spin-caps.com. Chrome plated brass for about $10 bucks cheaper than the ABS ones, billet aluminum at about half the price of ABS.
Not MicronAir but another good filter is Denso's. Got mine here: http://www.densoproducts.com/
Noticeably better quality than stock (triple layer). Just wish they were a little cheaper. Total for 2 with tax and S&H was $36.71.
The Japanese Toyota website,http://www.toyota.co.jp/Showroom/spc/surf/gallery/, has this clip and several others. You can also pick up cool wallpaper at the link labeled "present".
