case of function over form and built to the highest of military specifications including anti-magnetic shielding. The clocks were all individually numbered on a brass plaque and ran on two standard 1.5 V AA type batteries. When changing the batteries they can be exchanged one by one to keep the time running. A set of batteries provided power for circa 2 to 3 years. The 4.19 MHz technology was also used in Omega's range of LED timing equipment and prototyped in a wristwatch. The main movement of the watch was based on an Omega calibre 1343 Elan series but designated as 1522 it utilised a revolutionary 4.19 MHz micro quartz circuit, however there are only two known operational prototypes, one of which is now in the hands of a US collector and the other is in a collection in the UK. Summary In total Omega produced a rumored 10,000 calibre 1500 family watches (around 2000 were in spares), although revolutionary their cost was prohibitive and with the speed of development of quartz during the 1970s Omega wrote off much of the original R&D costs and towards the end of their production run Omega offered the remaining examples to Omega employees at 350 Swiss Francs, 1/10th of the retail cost. The Marine Chronometers and non Marine Chronometer calibre 1510 watches remain amongst the most significantly important Omegas ever made, one of the earliest quartz watches produced with an excellent accuracy, and to this day a serviced example will still be accurate to 1 second per month. External links 2400 article by Thomas Dick Useful Marine Chronometer information excellent source of Omega information excellent source of quartz and electronic watch information www.retromega.com www.old-omegas.com Megaquartz 2400 article by Thomas Dick Marine Chronometer Article by Thomas Dick www.swisstimeservices.com www.classicwatch.com References Omega watches