The Naef Bauhaus Design Optischer Farbmischer (Optical Color Mixer) toy is an origingal Bauhaus design by Ludwig Hirschfeld-Mack. It is a fascinating toy, whereby, a child can learn by playing; the rotation of the top demonstrates how colors blend together. There are 7 interchangeable discs with explanations of the different color theories for each disc. In action, the top looks like a kinetic piece of op art. A great opportunity for parents and children to play and learn together. The toy is handmade in Switzerland by Naef in cooperation with the Bauhaus Museum of Berlin. It is not intended for children under 3 years old.