I need to consider the following points when buying an outdoor flashlight:

1. Light output: in lumens (LM), it represents the energy collection of light from all angles of the flashlight light source. The light output of different flashlights ranges from 20 lumens suitable for reading to thousands of lumens.

2. Beam distance: in meters (m), it represents the distance from the point of origin of the beam to the point where the brightness is reduced to the minimum safety requirement.

3. The length of battery life: in hours/minute (H/Min), it is used to measure how long it takes for the light output to decrease to 10% of the rated output of the new battery. This represents the battery life of the flashlight. It mainly depends on the size of the power consumption of the light source, the size of the battery power and the current size of the drive circuit. It is the same for any brand.

4. Anti-dropping: When the flashlight falls on a solid surface, the degree of damage resistance that the flashlight can achieve. The product must not have any cracks or breakage, and all functions are sound, in order to pass the test.

5. Water resistance: There are three levels, IPx4 represents the water resistance of the flashlight against splashing water; Ipx7 represents the water resistance of the flashlight temporarily immersed in water; IPx8 represents the water resistance of continuous immersion in water.