минута в Google
тут и про курвиметр (левши не при делах) и про пластиковую крышку
Seiko Fieldmaster H801-6040 Ana-digi quartz
Release in 1991, I believe it was the first of the "map reader" watches. Its scale is 1/50000 so, even the biggest maps wouldn't have been hard to scale. With it, the compass bezel and many digital functions, trekking through the wilderness was made pretty easy.
Something this Fieldmaster has in common with the original is it’s plastic case back. The reference on this watch says it's a " frozen-resistant protector " I asked Mr. Tokunaga about it and was told the reason for it was, so it didn't stick to the back of your wrist from sweating while in extremely cold conditions. Make's a lot of sense. It also takes away from the weight.
