Limited edition of 77 pieces perrelet watch first class double rotor 20th anniversary limited edition a30501 known as a pioneer and pillar of the watch making industry perrelet are behind some of the most visually stunning and technically proficient timepieces in the industry the perrelet first class double rotor 20th anniversary limited edition collection was designed especially to celebrate the birthday of its double rotor invention a novelty that brought the brand into the forefront