link to this product (Special discount).
https://www.amazon.com/MindWare-44156W-KEVA-Contraptions-Plank/dp/B002V7YBNC/?tag=cheapsearch0b-20
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KEVA Contraptions Plank Set Reviews:
WELL DESIGNED CONTRAPTIONS: Unlike other Rube-Goldberg type toy contraptions, our KEVA Playset employs snugly, fitting non-warped pieces that don't have breaks or skips, meaning the ball will never move unpredictably or careen off. Guaranteed to entertain rather than frustrate!
INTERCHANGEABLE: These planks are the same size and shape of other Kapla or KEVA planks and thus can be used interchangeably with those systems to construct elaborate and expansive structures.
TOYS THAT TEACH: Our KEVA Contraptions are fantastic toys for teaching children to embrace their creativity and design engineering marvels. With 200 identical wooden planks crafted to be used as scaffolding, ramps, paths, and much more, this toy is perfect for any child looking to build and learn problem solving with basic physics. Who knows, in time you might have an architect on your hands!
NO HASSLE: With no glue or connectors needed, our KEVA Contraptions set is ready to play right out of the box. Forget the hassle of having to round up a laundry list of non-included tools. Simply unpack and build!
INCLUDES: Package includes 200 identical wooden planks, 2 balls, and 1 idea book with project photos and quick start instructions.

KEVA Contraptions Plank Set