The Royal Oak 15551ST is the self-winding 37mm Royal Oak — a case size that wears with equal authority across genders and wrist sizes, and which has rapidly established itself as one of the most commercially and culturally relevant additions to the Royal Oak range since the reference's 1972 launch. The light blue "Grande Tapisserie" dial with diamond bezel represents the 37mm at its most jewelry-inflected: the cold ice blue of the dial and the brilliance of the diamond-set bezel producing a configuration of considerable refinement while retaining the angular, brushed steel architecture that defines the Royal Oak's fundamental character.

The 37mm stainless steel octagonal case carries a diamond-set bezel between the characteristic eight hexagonal polished steel screws. The light blue "Grande Tapisserie" dial presents applied white gold luminous baton hour markers, a date aperture at three o'clock, and white gold baton hands. The integrated stainless steel bracelet with alternating brushed and polished links and AP fold-over clasp flows directly from the case. Caliber 5800, self-winding with approximately 55-hour power reserve, powers the movement.