This binary clock uses the BCD method (binary coded decimal) and is simple to read if you know how. It shows the local time of the viewers computer in the form of 24 lights that are either on or off. Included with the product is a text file allowing you to customize six aspects of the clock: the shape of lights (8 options), the colour scheme, the colour of lights turned on, the colour of lights turned off, whether or not to show numbers as well and the type of labels to show. And don't worry, there are instructions on how to read the clock!