Fatherhood is the Mother of Invention.

Enduro-Lume™ is the brainchild of Jon Weber, founder of PAR WEBER. After becoming a father in 2018, Jon was frequently up late at night to feed his infant son, Gabriel. Jon was frustrated by the Super-LumiNova watches in his collection - they were rarely legible when he needed them most: in the middle of the night. So he set out to design an electroluminescent system that could continuously illuminate a wristwatch at all times.


257 Prototypes in 180 Days.

Over the next six months, he made 257 prototypes. Each prototype progressively refined the system's electronics, form factor, and performance profile. In tandem, he searched out and secured manufacturing partners across the United States, and incorporated input to improve manufacturability at scale. Finally, he traveled to Switzerland to search out the right watchmakers to build the timepiece itself.


Legible, Tough, and Reliable. For Those Who Depend on Their Timepiece.

The result is The Coefficient, the first timepiece to be continuously illuminated by Enduro-Lume™. The Coefficient is made for those who rely on their wristwatch day in and day out. It does its job superlatively well: it's legible day or night, it's tough as nails, and it's unwaveringly reliable.  

Since the announcement of The Coefficient, we have been overwhelmed by the enthusiasm we've received from first responders, members of the military, and professionals working in all manner of critical infrastructure (healthcare workers, linesmen, field mechanics, and others). Thank you for all your input as we've developed the timepiece and for the critical work that you do.



Our first product, the Coefficient, is a wristwatch that features our patent-pending illumination system, Enduro-Lume™.

Enduro-Lume™ is a continuously operating electroluminescent illumination system. Twelve purpose-built light emitting diodes are concealed beneath the bezel. While other LED-based illumination systems can only run for a matter of seconds at a time in order to preserve battery power, specialized circuitry and precision materials engineering enable the Enduro-Lume™ system to clearly illuminate the entirety of the dial at all times, while achieving incredibly long battery life (up to 3+ years).

Enduro-Lume™ has significant advantages over the most common forms of wristwatch illumination: conventional glow-in-the-dark LumiNova® derivatives, trigalight® (tubes filled with radioactive tritium), and electroluminescent panels (e.g., Indiglo®).


Click table to enlarge


The Coefficient was designed with three major performance objectives: to be legible, tough, and reliable. It's made for those who depend on their wristwatch day in and day out.

The Coefficient achieves these objectives thanks to its high-contrast dial and always-on illumination system, the time-tested materials in its construction (PVD coated steel and a sapphire glass crystal), and a practical and extremely accurate Swiss-made quartz movement.

PAR WEBER designed the timepiece in Chicago and manufactures the Enduro-Lume™ systems in the United States (80% U.S. content). The Enduro-Lume™ systems are then built into watches themselves by partners in Switzerland according to Swiss standards.



Assembled in Switzerland with a Swiss-made movement and U.S.-made illumination system.

  • Enduro-Lume™ always-on illumination system (patent pending). Made in U.S.A. with 80% U.S. content.
  • PVD-coated 316L stainless steel construction
  • Zero-distortion flat sapphire glass crystal
  • 120-click bidirectional "aperture ring" bezel
  • 100M/330ft water resistance rating with heavy duty gasketed push-pull crown
  • Swiss-made Ronda 715 quartz movement


  • 43mm diameter
  • 14mm height
  • 48mm lug-to-lug length
  • 20mm-wide drilled lugs
  • 95 g weight (approx.)


Read more about the The Coefficient in our detailed discussion of PAR WEBER's design philosophy and specific objectives for The Coefficient here:



Demonstration: Enduro-Lume™ vs. Conventional Lume

The Coefficient: Prototype Walkthrough



PAR WEBER is an American company based in Chicago, Illinois. Our mission is to design and deliver superior equipment.

This means that our products:

  • Have clear performance and functional advantages
  • Are made to the highest standards of material and build quality
  • Are responsibly built, with supply chain partners we know and trust
Our first product, the Coefficient, is a wristwatch that features our patent-pending illumination system, Enduro-Lume™. It was designed at our headquarters in Chicago.



In the wee hours one morning in 2018, Jon was putting his infant son back to bed and found the conventional glow-in-the-dark pigments on his wristwatch had long run out. This simple frustration led Jon to begin development of a new continuously operating illumination system that ultimately matured into Enduro-Lume™.

Prior to founding PAR WEBER, Jon's career spanned three continents and multiple industries. He graduated from the University of Virginia with majors in Economics and Russian and went on to work at Washington, D.C.-based NGOs focused on human rights and rule of law in the former USSR. He then received an MBA from The Wharton School and worked for five years at The Boston Consulting Group in Chicago, serving multibillion-dollar clients in the healthcare and industrial goods sectors. He left BCG as a Principal following the birth of his first child.

Jon's formal engineering education was limited to high school coursework on electronics, computer science, and prototyping. Since then, he has remained an enthusiastic coder and electronics tinkerer.

Jon lives in Chicago with his wife and son.