The 4992B is based upon the excellent 21 jewel 992B Railroad watch, being converted to run with a sweep centre seconds hand which  requires an extra jewel to support the centre seconds pinion, raising the total jewel count to 22. The watch also has a hacking feature added which stops the movement when the crown is lifted to time set position, instantly restarting when the crown is then depressed to winding mode. This allows for highly accurate time setting and easy synchronisation with other time pieces. These watches are so accurate and reliable that all other timepieces within a unit were synchronised to them, giving rise to the title "Master Navigation Watch"

These watches were produced exclusively for military use during WW11.

The nickel split plate movement has 22 jewels, a fully capped Swiss lever escapement with the very latest "Elinvar" hairspring with solid mono-metal balance wheel, double roller, and a sprung micro-regulator. This was all cutting edge technology for the period. This particular movement is in excellent mechanical condition and super fine cosmetic order. It runs strong in all positions and keeps time to within a few seconds per day.

The watch is crown wind and crown set, both functions working smoothly.

The nickel plated case has screw on/off front and rear covers. The covers both remove and replace easily and both close down square and tight. The rear cover shows considerable wear to the original plating but this is fairly typical for these watches. The original engravings to the rear cover are still legible.

The original 24 hour black dial is in excellent condition with no chips or cracks and all of the printing is crisp and sharp. This is a 24hour watch, in that the hour hand rotates once in 24hours not the more usual 1 in 12hours. Thus the 12 is where one might normally expect to find the 6. The inner chapter are the hours 1 to 24 with the outer chapter the minutes 1-60 (also seconds) so reading the time takes a bit of thought.

The original white painted hands are in excellent condition and this all sits under a very good acrylic crystal.

Overall a super example of this iconic military timepiece in beautiful working order.

Thank you for looking and please check out the other fine watches I am currently listing.

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USA £40  Europe £25. Other destinations please enquire.

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