This folding ruler has a simple principle; 2 metres= 2000 millimetres=2000 years of history. So, in addition to a ruler you get a sophisticated selection of essential data from the past 2000 years. On the event side each centimetre represents ten years of world history, from Jesus’ birth to the spread of the internet. And, on the other side, as well as inches, history is divided into its fundamental periods (The Renaissance etc). Educational, original, practical and fun… and all in a ruler.