Brand: Wittnauer

Model: "Pert-o-Graph" Automatic Date ref. 7005 (RARE); Swiss Made circa 1960s

Case: Solid stainless steel case with screw-down caseback is approximately 40mm excluding the signed "W" winding crown

Bracelet: 20mm vintage-style stainless steel mesh bracelet (adjustable size via sliding clasp)

Movement: Wittnauer cal. C11KAS self-winding automatic movement (17 jewels) with date; 19,800 BPH; Swiss Made

Features: Super cool and unique white "graph paper" dial with black inlay hour markers at 6, 9, and 12 o'clock; date display at 3 o'clock (non-quickset); original non-luminous hands with black inlay; unpolished 40mm stainless steel case with original rotating slide-rule bezel; domed acrylic crystal with internal date magnifier; Wittnauer automatic movement (serviced)

Condition: Nice original condition overall with honest wear consistent with age and use; solid stainless steel case appears to be unpolished with the original bevels in tact; "STAINLESS STEEL" remains visible on the exterior of the caseback; very attractive original white "graph paper" dial; excellent original hands; clean domed acrylic crystal with internal date magnifier

Other: If you're looking for a unique and rare conversation piece, this undeniably cool Wittnauer "Pert-o-Graph" with slide-rule bezel would be an exquisite choice. HODINKEE recently sold a similar example and appropriately referred to it as "a watch built for the most advanced minds of the time. This slide-rule equipped Wittnauer has a very academic look that sets it apart. Developed in the 1960s, critical path theory in project management identifies the series of tasks needed to complete a project and prioritizes the tasks that require completing in a certain order to expedite the project, creating a critical path. The Pert-o-Graph is a slide-rule style computer that calculates critical path. Luckily, the Wittnauer "Pert-o-Graph" example we have here is fitted with a more standard and more usable slide-rule bezel." We absolutely love the white dial with its "graph paper" motif and matching black inlay on the hour markers and hands. This is a rare opportunity to acquire a nice example of this watch. As an added bonus, the Wittnauer C11KAS self-winding automatic movement was just completely overhauled by our watchmaker.