Techno Gears Marble Mania Mini Series is a great way to challenge your child’s building skills and introduce them to the Techno Gears Marble Mania line. The Slingshot set includes over 80 pieces to build and create your own marble and gear run. Once completed, the hand crank that turns the bucket and chain pulley systems will lift the marble to the top of the build where the track and the fun begin. All Techno Gears Marble Mania sets are interchangeable and will require a minimum of 1-2 hours of construction for completion. Ages 6+ years.