That may be a trap, but this one definatly is:
http://www.gunbroker.com/Auction/ViewItem.asp?Item=36237015
CZ26 parts kit and 50% receiver
Like new condition CZ26 parts kit that includes 4 magazines and all parts. The kit is demilled to ATF guidelines and is considered a non-firearm. The sale also includes a 50% receiver tube, which is the proper material and size. This kit can only be built into a working firearm by a properly licensed individual (class II manufacturer) or a non-working display if the proper ATF guidelines are followed. ALL NFA RULES APPLY
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Having both the complete FA parts kit and reciver tube is considered by the ATF to be Intent to build