OW P-104 SELECTRON

You may never have used a slide rule. Since the advent of the electronic calculator, few people have. However, before the 70s, slide rules were used for everyday arithmetic, such as calculating ratios, percentages, unit conversions, multiplication, and division. From the mid-century, wristwatches with miniature slide rule scales were used by scientists, engineers, and pilots to calculate things like fuel consumption, airspeed, ground speed, and the rate of climb or descent. Throughout the 60s Slide rule watches were ubiquitous amongst workforces in the burgeoning field of ‘aerospace engineering’, from NASA to General Electric. Ollech & Wajs ‘Selectron Computers’ were amongst the most popular slide rule watches of this period. Back then, the word ‘computer’ described a person who carried out calculations or computations, rather than a programmable machine capable of processing digital data.

The OW P-104 Selectron shares many of the basic characteristics of its historic forebears. It has a bi-directional bezel with logarithmic scales that can perform a multitude of calculations with a single rotation. It’s faster than a so called smartwatch, doesn’t require a battery and can be used underwater, up to 300m if necessary (that really is smart!)

The high contrast dial, which evokes the stark simplicity of cockpit instrumentation, features ivory indices and a vivid orange Super-LumiNova® handset, for maximum visibility in low light. The regimental-style RAF strap is another nod to Selectron’s historical links to military aviation. 

Inside the OW P-104 Selectron is OW’s own inimitable bespoke Soprod Newton Precision P092. This outstanding automatic calibre is independently tested for dependability and durability at the internationally renown Laboratoire Dubois in Chaux-de-Fonds. It is modified to OW’s specifications and adjusted in five positions, the movement has been finished in accordance with our rugged aesthetics, and ‘OW Zurich 1956’ is engraved into the nickel-plated base, on which sits a co-designed, custom rotor in the shape of the OW marque.

We mark the return of the Selectron with 56 special Numbered-Edition watches, which will be unique in two ways: The unique production number/56 of each watch will be engraved into the crown, and additionally these watches will be COSC-certified and come with official papers from Contrôle Officiel Suisse des Chronomètres (COSC), the Swiss Official Chronometer Testing Institute. 

The OW P-104 Selectron is presented on a regimental-style nylon RAF strap. The S-type ‘Beads of Rice’ bracelet can be purchased additionally as accessory for 256 CHF and a black handmade leather strap is an additional 96 CHF.

Model
OW P-104 SELECTRON

Year
2025 (launching with 56 special Numbered-Edition pieces)

Dimensions
39.5 mm × 15.8 mm

Case
Brushed 316L stainless steel, screwed back, screw-down crown, rotating bezel slide rule bezel, manufactured in Jura, Switzerland

Glass
Sapphire with anti-glare treatment

Dial
Hands orange Super-LumiNova®, indexes ivory Super-LumiNova®

Water resistance
300m/ 30atm

Movement
Automatic, bespoke Soprod Newton Precision P092; date-only calendar, with semi-instantaneous changes and quick adjustment using the crown; stop seconds; 4Hz 28,800 vibrations per hour; 23 jewels; 44-hour power reserve. The Soprod Newton P092 movement is independently tested for dependability and durability at the internationally renowned Laboratoire Dubois in Chaux-de-Fonds, Switzerland, and has been awarded a Chronofiable® certification. Exclusively for the first 56  Numbered-Edition pieces the movement is COSC Certified, thereafter COSC will be available as an optional upgrade.

Average Accuracy
+/-5 seconds per day, adjusted in five positions. (COSC version average accuracy +/-  in accordance with COSC tolerances)

Nylon RAF Regimantal-style band
20 mm, premium-quality,  black nylon with orange stripe one-piece band, made in Great Britain and highly durable. Hand-finished in Switzerland, with two brushed stainless steel keepers and a thorn buckle, signed ‘OWZ 1956’

S Bracelet (optional extra)
20 mm 316L stainless steel, beads-of-rice OW S-type Mark II, with double-lock deployant clasp (additional 256 CHF)

Black Italian leather strap (optional extra)
20 mm Italian leather, finished in Switzerland; with a brushed stainless steel thorn buckle, signed ‘OWZ 1956’ (additional 96 CHF)

Crown
Screw-down, engraved production number / 56 (Numbered-Editions only)

Origin
Handmade in the Swiss Jura

To request to reserve one of the 56 Numbered-Editions of this watch, e-mail reservation@ow-watch.ch with the following details:

 - Your full name
 - Your address
 - Your contact telephone number  

We will contact you soon after to confirm your successful reservation and to collect payment. Reservations are allocated in the order received. Shipping will commence early May 2025.

Free shipping by FedEx, which includes all import taxes, customs duties, customs clearance fees, VAT and handling fees.

For shipment to countries beyond  the European Community, Great Britain, Canada and the United States,  where the prepaid tax service cannot  always be offered, we offer our customers the  benefit of a special rebate,  via a 15% discount, corresponding to the average import duty and tax percentages in the countries listed above. This amount will serve as compensation for any such charges by local tax authorities.

Please note that the stainless steel bracelet should always be adjusted by a competent watchmaker.