Teach your kids the world of physics and engineering with the Tinkineers. Influenced by the fun of playing with basic STEM stimulation, this DIY mini coaster is a brilliant and basic first set for your youngest engineer. The STEM concepts in this particular piece are all about the conservation of energy and potential and kinetic energy. Use the crank to lift your marbles and watch them fall! Made of laser cut balsa wood, this coaster takes about an hour to put together and all your need is glue.