Techno balls 129 piece marball run
This amazing set lets you build your own gravity defying self perpetuating roller coaster then release your marbles on an enthralling ride through white knuckle twists and turns loop the loop and high speed straights until they reach the end the excitement doesnt stop there though because they will be automatically lifted to the top and off theyll go again the perfect gift for anyone with a love of science kit building or just fantastic gizmos