Helix Marble Run is part of the Award Winning Engenius Contraptions range. Once constructed, the motor-driven lift raises a column of marbles which are then ejected one by one down a mini slide. As the marbles drop off the slide they land on a series of miniature trampettes, bouncing from one to the next. The marbles then return to the base of the lift via the spiral hopper. Easy to build with click-together parts, and made from precision laser-cut plywood. It's a brilliant and stimulating construction kit that has a guaranteed wow factor. The finished size is 800mm x 220mm x 240mm