Q: Is the vacuum cleaner safe to use under extremely hot conditions? A: The vacuum cleaner has been tested repeatedly and has no safety problems when used at a high temperature of 70℃. Q: Is it safe to charge the battery at high temperature? A: The vacuum cleaner has over-temperature protection for charging. When the temperature is higher than 50℃, charging will stop. Q: Can the vacuum cleaner be brought on the plane? A: The vacuum cleaner uses a lithium battery and can be taken on board (consigned). Q: What is the filter of the vacuum cleaner? A: HEPA Q: Can the filter be washed with water? A: It can be washed with water. It should not be soaked during washing, just rinse. In order to maintain better suction, it should be completely dried before washing before use.