Rolex Datejust 178278

Reference 178278 is the solid 18k yellow gold, fluted-bezel model from the 31mm ‘Mid-Size’ Datejust 178xxx series, produced from c. 2006 into the late 2010s. This series is technically significant for introducing the heavier, modern case with fully polished lugs and the solid-link President bracelet to the 31mm size. It is powered by the Rolex Caliber 2235, a 31-jewel COSC-certified chronometer. As the successor to the Ref. 78278, it represents the modern iteration of the classic solid gold Mid-Size Datejust, featuring improved manufacturing tolerances and greater material substance.