... GB 14048.5 standard.2,Meaning Of The Button"A" means with total power switch, "no letters ... means with start and abrupt stop switch3,Working Conditiona, air temperature around for:-5 degrees to + 40 degrees, ... at the highest temperature for + 40 degrees, air relative humidity of no more than 50%, and ... under the low temperature can allow a higher relative humidity, such as + 20 degrees, ...