Experience the power of gravity! gravitrax is the all new stem track system from Ravensburger! use your imagination to build superb tracks and set the gravity spheres rolling! this stem system [science, technology, engineering and maths] is an ideal one to teach kids about gravity, magnetism, kinetic energy and fun. Hit a snag? freestyle with your own track design or use the tasks and blueprints included to help you to get started in the world of gravitrax! are the gravity spheres stopping or flying off before reaching the end target? time for some problem solving. Rebuild and try something different! the gravitrax track system can be extended indefinitely with extra track packs and add-ones each sold separately. This set is suitable for 1+ players, ages 8 years and up. The gravitrax loop with add another element of fun to your layout. You will however need to figure out how much momentum the gravity sphere needs to make it around the loop. Great fun! set includes 1x set of instruction, 1x loop base, 1x long rail, 2x medium rails, 3x short rails.