Run around corners, edges, and large obstacles! With the "Flex Corner" extension, every KOSMOS Gecko Run marble run becomes infinitely flexible. Whether a window frame is in the way, a gap between the fridge and shelf needs to be bridged, or it’s built around a cabinet – all of this is now possible! Simply place one of the two Flex Corners between two track elements, and the marble will roll around the curve. Additional track elements increase the range of the run and open up completely new possibilities. Ever built in a crisscross pattern? Just give it a try and build anywhere that is smooth and vertical!.