its likely because they are military grade phones resistant to extreme conditions. i pulled this from the specs,
Rugged Design
Certified to Military Standard 810F for dust, shock, vibration, temperature extremes, blowing rain, humidity, low pressure and solar radiation.
Rain Resistant
Certified to Military Standard 810F for blowing rain and humidity.
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also, check this out if you want miliatry grade! it even runs winmo!
One Bloody Ugly and Expensive Ultra-rugged Handset from AIS ยป Phone Reviews