Luxury Swiss watchmaker Oris, known for manufacturing only mechanical watches, released Oris Big Crown X1 Calculator into their aviation line at BHG Bugis on Fri, Jul 1.

The watch, designed as a tribute to the Bell X1 Supersonic plane (which was the equipment used for the first manned supersonic flight in October 1947) features a circular slide rule, hence the name "calculator".

Though quite commonly used in aviation, the slide rule takes a bit of getting used to, but will definitely come in handy for the mathematically-challenged who need to do some multiplication or division without an electronic calculator.

Visit http://www.oris.ch for store locations and more information.