Generally, led lamp beads of high-intensity flashlight have a long luminous life, and torch manufacturers generally mark them as more than 100,000 hours. In fact, attention should be paid to the brightness attenuation period of led lamp beads. The attenuation period of luminance is closely related to the material technology of LED production. Generally, under the condition of economic conditions, four-element LED with a slow attenuation of luminance should be selected. 
LED flashlight with strong light IPX waterproof rating:
Ipx-0 has no waterproof protection
Under normal operating conditions, the ipx-1 device provides the equivalent of 3-5mm/min of rain water protection for 10 minutes.
The ipx-2 level is basically the same as the ipx-1, but can pass a waterproof test with 15 degrees of upwarping in all directions.
The ipx-3 splash waterproofing at 60 degrees is provided with a two-to-five-minute 10 litre/s flow rate and 80-100n/m pressure waterproofing.
The ipx-4 level is basically the same as the ipx-3, but offers full and angular splash protection.
The ipx-5 is fully and angular waterproof, providing a two-to-three-minute flow rate of 12.5 liters per second and 30n/m pressure protection.
The ipx-6 wave is waterproof and can withstand a depth of 3 meters, a flow rate of 100 liters per minute, and 100n/m pressure for 2-3 minutes.
The ipx-7 can be submerged for 30 minutes in 1 meter of water.
The ipx-8 is completely waterproof and can be used continuously in water at all times. At present, the IPX8 waterproof level of flashlight is the best waterproof protection.