Cartier's Ballon Blue collection made its debut in 2007. The watch boasts a sleek, round case that resembles a smooth pebble. A standout feature of this line is the protected crown, which creates a slight dent in the dial for added character. The W69016Z4 model is crafted with a durable stainless steel case and features a classic silver dial. It runs on the self-winding caliber 049 and comes with a stylish leather strap.