Things really start to roll for little ones: the barrels, balls and rotating disks allow kids, in a playful way, to delve into the fascinating world of optics and discover impressive motion effects. Contents: 3 basic wheel chassis, 1 set of wheels, 2 effect balls, 1 spinning top, 6 color disks to stick on spinning top, 8 barrels, 1 ringing roll. Material: beech wood, polycarbonate.