1 of only Three I know of.
Released/Sold by ZIRCON.
My best guess is these were either, part of an early test run
by Fairchild and then mixed in with the regular releases when
Zircon took over, Or maybe a mistake by Zircon when doing their
own second production run. Either way these seems very limited
in number available.
Ebay auction link
http://www.ebay.com/itm/131478030903?rmvSB=true