This Casio PRG-270-1 belongs to Casio's ProTrek series. Compared with the PRW series, it has no radio wave timing function, but it has added the dual display function. It is also a popular mountaineering watch. Driven by solar cells, it can be used at a low temperature of - 10 ℃. Digital compass function, thermometer, altimeter, barometer, and world time function are all available. Dial straight