The Patek Philippe Ref. 5101P is the first timepiece that accommodates, in the confines of a wristwatch case, two complications which require a considerable amount of space: tandem mainspring barrels for a power reserve of 10 days as well as a tourbillon that rotates about its axis once a minute and can be viewed through the sapphire crystal caseback. 10 Day Tourbillon Manual winding Seconds subdial at 6 o'clock 10-day power reserve indicator Water resistant: 25 m Sapphire crystal case back Salmon dial Strap widths Case x Buckle: 20 x 16 mm
Case dimensions: 29 x 49 mm.