Patek Philippe, Ref. 2451, water-resistant “Calatrava”: This reference is launched in 1949 and remained in production until the late-1950s. This watch is fitted with the manual-winding Cal. 10-200. The majority in yellow gold, more rarely in stainless steel and pink gold. This model is so-called “Acuatic” by collectors. Kept in very good condition with 2 clear hallmarks on the case and a mint dial it has maintained its original dust cap and would only need a light polish to bring it to excellent condition.