Escape the castle's rotating tower with this exciting Quadrilla set, complete with two transparent staircases. As the marbles make their way down the rail, they ring three hanging bells. Start by building one of the examples shown on the box. Watch your marbles navigate the spiraling curve, blocks, and transparent staircases, ringing the bells as they race down to the catcher. Now use your imagination to build your own fantastic marble runs! Features • Marble run construction toy made with sustainable wood and non-toxic water-based paints • Includes 15 distribution blocks, a rotating tower, 4 tight turns, a big turn, a spiral twist, 6 height adjusters, 4 stabilizer rings, 8 accelerators, 2 gap closers, 2 transparent stairs, 3 bells, 3 universal clamps, 50 marbles and a catcher • The transparent stairs and bells add a new look and sound to the Quadrilla experience • The catcher makes it easier to catch the marbles at the end of the race • Endless possibilities to change the layout. See enclosed guide • German-made design inspired by the Da Vinci Circle • Helps develop spatial thinking and an understanding of science, technology, engineering and mathematics (STU) principles • Touted by The Wall Street Journal as the perfect toy to teach kids to code • Compatible with all Hape Quadrilla sets • Suitable for ages 4 and up