Early Polarouter and Polerouter Plexi’s

How to differentiate between some of the early reference plexis. SPOILER ALERT: All Polarouter/Polerouter plexis are signed!

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Early Polarouter and Polerouter Plexi’s

Since UG as a manufacturer has been essentially defunct since the 80’s, finding an original Polerouter with all the correct parts can be difficult at the best of times. Finding the correct, original parts to restore one can be equally difficult – particularly when there is limited information on what exactly you should be looking for. 

Inevitably, barn-find examples have surfaced which have helped to quash old rumours such as “not all Polerouters or Polarouters had signed crowns” and “not all had signed plexis” – typically whispered by sellers of pieces which are lacking one or the other. We have seen enough “untouched” examples that as a community we can now say confidently that all Polarouters and Polerouters had both signed crowns, and signed plexis. These details can make a huge difference in collectability, and there are fine differences between the geometries of correct parts for each model.

Movement CaliberModel ReferencesDiameter (mm)Features
Polarouter138ss20214/2021730.1squared edge - tensioned by inner rehaut
Polerouter138ssS 20214/2021729.1 (inner) 30.3 (outer)lipped edge - held in by screw-in metal ring
Polerouter138ssS / H 20214/20217 (approx 178xxxx serials onward30.1slight rounded edge, inner tension ring (different to 20360)
Polerouter215 microtor2035729.6rounded edge, inner tension ring
Polerouter215 microtor2036030.1rounded edge, inner tension ring

Above: The etching found in the middle of all Polarouter/Polerouter Date and non Date plexis. The etching is on the inside, so cannot be removed by polishing of the outside.

The Polarouter plexis were fitted from the outside of the case, and held in place with the inner marker ring which also doubled as a tension ring against the plexiglass (more details on page 6 of UG Technical Note 2). There was a case design change between the Polarouter 20214/20217 and the Polerouter S and H 20214/20217, which also meant new plexi designs and mounting styles. Although the updated plexis kept a similar flatter profile, the diameters changed, and the new plexi design for the S-cases was now fitted from inside the case, held in with a one-piece metal tension ring that screwed in behind it to lock it against the case. The H-cases also kept the same flatter profile, but returned to the style of mounting from the top, and utilising a thin tension ring (more details on page 9 of UG Technical Note 3). With the introduction of the Microtor models, the plexi was again press-fitted from the outside utilising a seperate tension ring, and was given a new profile which had much more rounded edges – a feature which was kept through into the 70s. 

Above: UG technical note for fitting a Polarouter 20214/20217 plexiglass (top) and Polerouter S20214/S20217 plexiglass (bottom). Also pictured is the UG tool for tightening the screw-in metal ring, that kept the plexi in place (bottom).

Above: Visual difference between Polerouter S20217 (left), Polarouter 20217 (middle), and Polerouter Microtor 20357 (right) plexis.

Above: Visual difference between Polarouter 20217 (left), Polerouter S20217 (middle), and Polerouter Microtor 20357 (right) plexis.

Most microtor models continued with the same round-edge plexi profiles, however the diameters varied according to each specific model reference. There are over 20 different Polerouter plexi sizes/types, and we will be adding these sizes to the reference tables in the main menu to help polerouter collectors find the right parts they need for their model reference.

How do I know if it is the correct plexi for my Pola/Polerouter?

Non-Date models – Firstly, no matter what, it should be signed with the U Shield in the centre of the plexi. This can be hard to see, especially if the plexi has some scratches, the photos are poor, or the lighting is at the wrong angle. Beyond the S-case bumper models, they should all have a tension ring inside the plexi that matches the colour of the case – steel or gold. The exception here is the 10234 18K models, which appear to have been the first in the range to use this type of seperate inner tension ring. Beyond this, the generic rule is that if it fits, then it is quite probably correct. If in doubt, measure the plexi size of your case with calipers, and add 0.1-0.2mm to this (they are a press-fit, so the tension ring causes it to expand when not fitted).

Date models – For steel and capped/plated Date models, these all came with a loupe over the date window. Reference 204503 (steel) and 204504 (gold-cap) were the first Polerouter Date models to be offered by UG, and are shown to have a round-shaped loupe in the vintage advertising. After this model, all references are shown to have plexis with the trapezoidal date loupe, including the Sub (date) and Super models. The most common date plexi size is 30.6-30.7mm diameter, which appear to fitted somewhere around half of the date models, such as 204605, 204607, 204610, 869111, 869113, 869115, 869119 amongst others. Again, the rule is if in doubt, measure your case for size and add 0.1-0.2mm.

Collectors Note: “Undesignated” dials

DIY: Replacing a crown and stem on a Polerouter

Investigating the Polerouter Sub 20369/1