The Calculator has a following among those seeking cool tools of industrial design from the past. Although it can look a little clunky and large at first, it can actually be quite comfortable and cool on the wrist. The first thing you notice is the two-layer slide rule on the bezel. The outer ring rotates and the inner ring remains fixed. The slide rule is designed to measure distance and also convert weight and volume from the imperial to the metric system and vice versa. Keeping all the slide rule portion on the bezel allows the dial to remain uncluttered, retaining a classic Heuer look from the 1970s with the bright neon hands and the subdial markers with a date at six.