Flashlights

Maximum beam distance

• Light output is measured in lumens (lm). Flashlights with a narrower beam have a longer beam distance even if their light output is identical.
• Some models have multiple brightness settings.

Power

• Smaller flashlights with more modest light output are commonly powered by button cells.
• Most types use AA or AAA batteries. They are inexpensive and easy to buy and replace.
• Powerful flashlights are energy-intensive, so they are equipped with rechargeable batteries.

Lamp life

• Flashlights with high light output tend to have shorter run time or higher weight, since they have to accommodate multiple batteries.
• LEDs themselves have a lamp life of tens of thousands of hours, all the way up to one hundred thousand hours.

Other features

• Increased mechanical durability  – these flashlights are resistant against vibration and shock and are generally made of hard plastic, light and tough metal alloy, and can have rubberised components.
• Water-resistant - resist fog and rain, but cannot be immersed in water.
• Waterproof - can withstand immersion in water.
• Tilting lamp - useful when you need to illuminate less accessible spots.