IWC Schaffhausen Portugieser Hand-Wound Tourbillon Day & Night

The IWC Schaffhausen Portugieser Hand-Wound Tourbillon Day & Night IW545901 has a case in 18 ct Armor Gold measuring 42.4 mm across. The case stands 10.8 mm thick and carries a 6 bar water resistance rating, equal to 60 metres. A manual-winding, IWC-manufactured calibre 81925 drives the watch, with 84 hours of power reserve. The black dial shows a day and night display and sits beneath a convex sapphire crystal with antireflective coating on both sides. IWC fits a display back so the movement can be viewed from the reverse. The calibre 81925 runs at 28,800 vibrations per hour and is built from 195 components with 22 jewels. A black alligator leather strap by Santoni, 22 mm wide at the lugs, accompanies this reference.