Once completed they simply drop the marbles into the top of the track and let the fun begin! The color instruction manual provides step by step instructions for building whirler but you can make your own designs too! Manufacturered by The Learning Journey. All Techno gears marble Mania sets are interchangeable and will require approximately 2 hours of construction for completion For ages 6 and up Techno gears marble Mania crazy Trax is a great way to challenge your child's building skills
