On the left, the Premier Excenter Perpetual Calendar in white Gold, 2007 edition, on the right, the Premier Excenter Perpetual Calendar in platinum, 1987 edition, a limited edition of 20 pieces. The original Premier Excenter Perpetual Calendar with its innovative design was the pioneering timepiece that established Harry Winston’s identity as a master watchmaker. It was also one of the first timepieces to introduce and popularize retrograde indicators. Diameter of the case: 41mm Movement: automatic Material: white gold or platinum Reference: 200/MAPC41WL.A for white gold Reference: 200/MAPC41PL.KC for platinum