In math, irrational numbers are those that can't be represented by simple fractions.
Two examples are pi and the square root of 2. Designed by a mathematician, for mathematicians (and others in the know, like engineers and scientists), this clock tells time in irrational numbers logically placed on a 360-degree circle. For example, pi (3.14159...) is just a few degrees past where the 3 would be on a regular clock face.
Black with white markings and hands, metal clock runs on 1 AA battery. 12" diameter.