Cartier Tank Solo, model number 3169. The Cartier Tank Solo measures a 27×35 mm stainless steel case, a smooth stainless steel bezel and sophisticated bracelet. The Cartier 3169 features a white dial with the classic Cartier-style black Roman index hour markers and blue hands. This Cartier Tank Solo features a quartz movement with a sapphire crystal on top. Between the watch’s crown guards, you’ll find the outstanding blue sapphire-tipped crown.