The TAG Heuer Carrera Chronograph Tourbillon CAR5A93.FC6442 is a limited edition of 155 pieces introduced in 2018. It features a blue ceramic case with several parts such as the case back in PVD-coated stainless steel. IThe complete watch -rather than the uncased movement- is tested and certified by the Besançon Observatory, earning it the 'Tête de Vipère' (Viper's Head) stamp.