The Cartier Ballon Blue line was introduced in 2007. It features a smooth, pebble-like case. One of its signature elements is the recessed & protected crown and the ‘dent’ it causes in the dial. The Extra Flat 46mm was introduced in 2011, while the Extra Flat 40mm was introduced at SIHH 2015.Reference W6920105 has a white gold case of 39mm, which houses its hand-wound caliber 9452MC with flying tourbillon. The guilloché dial is covered with blue translucent enamel.
