This Royal Oak reference 6009SA takes the line in a different direction, with a rectangular ultra-slim case that still keeps Audemars Piguet's sharp geometry intact. The stainless steel and yellow gold case and matching bracelet set up a champagne dial with a dressier feel than the usual sport-forward Royal Oak look. Its quartz movement helps keep the case to 6.3mm thick. At 29mm by 39mm, it sits neatly under a cuff and wears with clean proportion.