Klutz Lego Chain Reactions Science & Building Kit, Age 8

Amazon.com Price:  $15.14 (as of 29/12/2019 17:08 PST- Details)

Nappa silver award winner
Design and build 10 amazing moving machines – teach your bricks new tricks
Comes with 80 page instructions, 33 LEGO pieces, Instructions for 10 modules, 6 plastic balls, string, paper ramps and other components