The Tank is a line of watches made by Cartier. It was created by Louis Cartier in 1917, and inspired by the new Renault tanks which Cartier saw in use on the Western Front, and the prototype watch was presented by Cartier to General John Pershing of the American Expeditionary Force. Its lines and proportions are similar to those of tanks found on First World War battlefields; it is both a square and a rectangle, and its straps are concealed under vertical sidepieces so as to be hidden from view. Tanks (usually) have blue, sword-shaped hands with silvered opaline guilloché dials. The winding crowns on Tanks, like those of most Cartier watches, have sapphire cabochons on them. It is possible to find most models of Tank in versions embellished with diamonds. The metal bracelets on those models which come with them (such as the Tank Française) are shaped with indentations which bring to mind the distinctive caterpillar tracks of real tanks. There are now over thirty variants of Tank watch, in both automatic and quartz versions, and it has inspired countless copies with its classic design. The most recent version of the Tank is the Tank Française, released in 1996.