"Waterproof Cooling Fan" dust levels: 0: no protection; 1: to prevent large solid intrusion; 2: to prevent the intrusion of solid medium-sized; 3: to prevent intrusion into the small solid; 4: to prevent solid objects greater than 1mm into the; 5 : against harmful dust accumulation; 6: completely prevent dust from entering. Waterproof: 0: no protection; 1: water droplets trickle to the housing no effect; 2: when the housing is tilted to 15 degrees, the water droplets trickle to the housing no effect; 3: water or rain water from 60 degrees corner to no effect on the housing ; 4: liquid splashed in any direction from the housing does not hurt impact; 5: wash with water without any harm; 6: can be used inside the cabin environment; 7: submersible (1m) at short resistance; 8: at a certain pressure prolonged soaking.