The new ZF model debuts the Audemars Piguet Royal Oak Anniversary 15510ST series. The new 15510 removes the AP logo, opting to retain only the full name Audemars Piguet, and features the logo craftsmanship from the CODE 1159 with finely detailed three dimensional branding. The automatic rotor has been changed from the AP colored rotor to a silver one with lettering, giving it a more structured and vintage appearance. The movement is based on the 9015 modified to the AP.CAL4302, offering superb stability. With a watch size of 41mm, if you haven t yet acquired the Steel King, you can opt for this more affordable option. Smirking.