The Cartier Ballon Bleu 42mmde Cartier Carbon Watch 42 mm Automatic Black Dial & Alligator Strap Deploy (Ref. WSBB0015) is a Steel-cased luxury mechanical wristwatch. The dial is Black. Powered by a Automatic movement. It wears on a Alligator skin strap/bracelet. On the secondary market across 1 active listing. When buying pre-owned, check condition grade, box and papers (typically a 10–20% premium), service history, and originality of dial and hands. Use the listings and price history on this page to benchmark fair market value.