1: Light Output. This is measured in lumens, and the more Lumens, the brighter light.
2: Run Time. Run time is commonly given for each light setting.Light output may gradually decrease by time,maybe it will remain largely constant and then suddenly decrease.
3: Beam Distance. This is measured in meter.It vary with the brightness setting you select.
4: Water Resistance Rating.This is rated using the IPX system.IPX4 rating is splash resistant from all angles.
5: Impact Resistance.This is measured in meter. How well will your flashlight survive after occasional accidental drops.
6.Size and weight.Is it easy to carry and storage？How does it feel in your hand?
7.Battery.This is the key part for the flashlight.The capacity,type and availability of replacement batteries are different.
How do you choose a newly led flashlight?
Which factor will you consider first?