This watch is also known as: 5136-1G 5136/1G 5136/1G The Patek Philippe Classique Grande Complication Model # 51361G (51361G or 5136G) features hours minutes and perpetual calendar with moon phases day date month leap year and AMPM indication. This automatic self-winding mens watch utilizes Patek Philippe Caliber 240 Q engine with 27 jewels 21600 vph 275 parts and 48-hour power reserve. The Patek Philippe Classique Grande Complication 51361G in 37-mm 18K white gold case with fixed bezel and bracelet with butterfly clasp with flip-lock also comes in interchangeable solid back and sapphire crystal back and 18K white gold fluted crown. An anti-reflective sapphire crystal covers the Patek Philippe Classique Grande Complication 51361G silver dial with stick indicators and three silver sub-dials -- month and leap year sub-dial at 3 oclock position date and moon phase sub-dial at 6 oclock position and day and AMPM indicator sub-dial at 9 oclock position. This functional timepiece is water resistant to 25 meters (82 feet) which makes it suitable for splashing and light rain but not for swimming and diving.