ZenithChronomaster Open Power Reserve

For over a decade now, Zenith’s El Primero 4021 movement have been beating inside their Chronomaster line of watches. Much like Zenith itself, this collection had its ups and downs only to finally become stronger and more appealing than ever.

This specific model is a lovely connection between Zenith’s historic designs from the sixties and seventies and its more modern looks. The case, in stainless steel with a diameter of 42mm, definitely has a considerable retro feel to it with its sharp lugs, thin bezel and its piston-style chrono pushers. On the other hand, owing to the opening of the dial, there is a lot of action constantly going on.

First of all, there is the balance wheel performing 10 semi-oscillations every second, then there is the interaction between the escape wheel and the pallet fork – coloured purple and blue, respectively as they are formed from anti-magnetic, lightweight silicon. Finally, the fourth wheel with a tiny ‘propeller’ attached to it to act as a seconds hand. Whenever the watch is running, this aperture gives a very modern and dynamic touch to the otherwise retro look.

The lovely faceted hour, minute and small seconds hands all are easy to distinguish and make reading of the time easy while also providing a very striking appearance to the watch.

The movement inside is based on the incredible El Primero dating back to 1969 when it debuted as the first wristwatch calibre with both automatic winding and chronograph functions. For the 4021 version of it, the list of features is extended by another – really useful – addition. A power reserve indicator located on the dial at the six o’clock position. The ‘reserve de marche’ is approximately 50 hours which is highly respectable, but in this case you need to remember that as a 5hz movement, it uses a lot more power.

The movement consists of a staggering 248 parts, including Zenith’s skeletonised rotor with the star logo in the middle, suspended on ball bearings for sufficient winding. The El Primero has long been acknowledged as one of the most reliable and accurate automatic chronographs. A black alligator strap completes a very noble piece.

The piece is presented in excellent condition throughout with no perceptible marks to the case, caseback or bezel. Box, papers and accessories are all present and correct in mint condition and the alligator strap is superb. 

All watches offered for sale are searched and cleared against The Watch Register database and a certificate is available to the winning bidder upon request.

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