M series
Warranty: 5 years
Operating Temperature: 100% load at -40°C(can be lunched)~+50°C

Click here for M series power supply


H series
Warranty: 3 years 
Operating Temperature: 100% load at -20°C(can be lunched)~+40°C and -10°C(can be lunched)~+40°C

Click here for H series power supply

Please take the lifetime of products and the operating environments into account when you're thinking about which one of the series is the one you need.