What does Mil Spec 810 mean?

810 is a series of tests in the Military Specifications manual. C, D, E, and F are particular test conditions under section 810. The RM, RDX, CLP, CLS, DTR and DLR radios have met or exceeded Mil Spec 810 C through F. These tests consist of Shock, Rain, Temperature Shock, Sand and Dust Intrusion, Extreme Temperatures, Humidity and Salt Fog.