Product Details
 
SKU Code: GMT/SS/SILB/QZ
This GMT dual time zone watch in stainless steel finish is one of our latest watches and has a high performance quartz Ronda 515.24 movement, an anti reflective and impact resistant sapphire crystal and scratch resistant ceramic bezel, the robust 300m / 1000ft water resistant steel casing also makes the watch ideally suitable for use in water for swimming, snorkelling and water sports although as a GMT watch the bezel is designed to enable time to be calculated in two time zones so for diving applications its suitability is rather limited although from a water resistance perspective the watch would be fine.
The concept behind GMT watches is very clever not because they are in any way particularly complex but because the technology behind them is so incredibly simple. On a conventional watch the hour hand is designed to travel around the dial over a 12 hour period, all that is needed to create a GMT watch is to add a second hour hand which travels around the dial in 24 hours instead of the usual 12, then an additional 24-hour time scale is added to a bezel hence the reason some GMT watches at quick glance look similar to divers watches. Using the watch could not be easier because the 24-hour hand circles the dial once a day instead of twice with a normal hour hand, its tip indicates the corresponding hour and because it’s operating on the 24 hour timescale there can be no confusion between a.m. and p.m.

We initially produced these watches for long haul airline pilots and also military pilots flying transport planes such as the Lockheed C-130 Hercules and Airbus A400M because the watch enables them to see the time in both the departure and destination time zones.

The watch measures 46mm including the crown and 43mm excluding the crown.
Dimensions and Specification: 
300m / 1000ft Water Resistant
Movement: Ronda 515.24 
Stainless Steel case
Ceramic Scratch Resistant Bezel 
Screwdown crown
Width Inc Crown 45mm (Exc Crown 40mm)
Thickness 15mm
Sapphire Crystal with anti reflective coating *
Crystal Diameter 31mm
Lug to Lug 49mm 
Silicon Strap and 2 x 20mm NATO Webbing Straps (One Black and One Grey)
If you would like to see details of the operation of the Ronda 515.24 GMT movement please click this link http://www.ronda.ch/fileadmin/user_upload/Products/TA_BA/ba/BA_neu/BA_500.700.1000.6000.7000_Basic_en.pdf
* A lot of people ask us what are the benefits of sapphire crystal over a standard mineral crystal? The answer is that synthetic sapphire is by far the best material for watch crystals because it is very strong and also shatter and scratch resistant, these characteristics make it very appealing to military and security personnel, police officers and people who lead active outdoor lifestyles, these groups account for over 70% of our customers. To get things into perspective we find that when clients have accidents with watches resulting in a cracked crystal over 90% are usually watches with mineral glass crystals, even factoring in that we use hardened mineral crystals they still do not come close to sapphire for durability under adverse conditions. The reason that sapphire crystals are so strong is that after the sapphire glass is manufactured it is also heat-treated to remove its internal stresses—which can cause weakness—it is then made into the watch crystals and two layers of anti-reflective coating are applied, interestingly sapphire crystal is now used on the latest iPhone. Of course sapphire crystal comes at a price hence you find that it's normally only fitted to higher end watches.