The Royal Oak 15451 made its first appearance in 2012. Its case measures 37mm across and features a bezel set with 40 brilliant-cut diamonds. Like its non-diamond cousin 15450, it is powered by the self-winding caliber 3120.Reference 15451OR.YY.1256OR.01 was added to the collection in 2018. It features a gem-set bezel with eight different shades of brilliant-cut orange sapphires, meticulously graded from pale to dark.