The Fibonacci number sequence is a series of integers in which each is the sum of the two that precede it: 1, 1, 2, 3, 5, 8, 13, etc. From right to left, that sequence is portrayed by the number of holes in each column. Red anodized aluminum, sandwiched between two pieces of black-dyed hardwood, matches the red hour, minute and second hands. Continuous sweep, silent quartz clock movement, AA battery included.