K'nex Krackens Revenge Thrill Rides Roller Coaster Building Set. Never really played with...few bits missing. Hasn't been constructed so I'm not sure what is missing, my boys emptied it out of the box but lost interest (they prefer Lego) ...needs someone to put it up to find out. The motor works and the rest is in good clean condition. Great present for an enthusiast.
eBay