3 Answers

....timing 

....mode

....two-way communication

....ascertain reception and listening skills

....differentiate informative, priority and emergency 

The 43.5mm sizing might seem like a modern affectation. After all, we still consider the Speedmaster to be a large watch for its time at 42mm. But 43.5 was the size link of the original ref. 88510/01 and so the Lunar Pilot is faithful in its sizing. That original model beat link with a mechanical chronograph movement, likely some form of Valjoux variety where link the modern Archive series watches – including the Meteorite edition – is powered by the high-precision quartz caliber NP20.

My wonderful little Vacheron link is the end result of a long strange and informative trip. I've learned that link I adore straight-up dress watches and small ones at that. I've also learned that I feel more like myself in these relatively dainty timepieces from yesteryear. link What that says about me I have no idea but age has given me the freedom not to care so much.