"Cross Flow Fan" marked the second feature number (numbers) within the meaning of the degree of protection: 0: no protection no protection. 1: prevent dripping invasive vertical drops of water droplets (such as condensation water) on the lamp will not cause harmful effects. 2: When tilted 15 degrees can still prevent drip invade when the lamp is tilted from vertical to 15 degrees, the water dripping on the lamp will not cause harmful effects. 3: to prevent intrusion of water spray of rain, or to prevent a direction perpendicular to the angle less than 60 degrees by spraying water into the fixture damage. 4: to prevent splashing water splashing from all directions to prevent the intrusion of water into the fixture damage. 5: to prevent the intrusion of water sprayed in all directions to prevent their exit from the nozzle of the water entering the fixture damage. 6: to prevent the intrusion of big waves lamps installed in the deck, and prevent the invasion of big waves and into damage. 7: to prevent flooding when water intrusion lamps soaked in water for a certain time or a certain pressure to ensure that these standards are not caused by water damage. 8: to prevent the sinking of water intrusion lamps indefinitely sank under the specified water pressure conditions, to ensure that no damage caused by water.