5W LED headlamp 9~12 hour lighting, up to 300M distance

5W LEDs (a type of semiconductor) as their light source. Cool white and natural white option, please choose it from below listed.

Beam Distance: 300M, High-intensity beam
•Reported in meters.
•Determined when batteries (the same type sold with the headlamp) are new.
Lumens tell you how brightly a headlamp glows (at its source), but not how far it goes (to a surface you want illuminated). This is a headlamp's fundamental purpose—to channel light to a target area.

Headlamps are tested to determine how far (in meters) they can project usable light, defined as the light cast by a full moon on a clear night. In the lighting industry this is known as the "moonlight standard," which is especially relevant to outdoor adventurers.

The light of a full moon, unless obscured by a dense tree canopy, is considered sufficient light for a person to navigate cautiously but safely through outdoor terrain.

To meet that standard, a light meter must be placed on a surface and register a minimum reading of 0.25 lux (the light intensity of a full moon). Lux is a measure of light where it falls on a surface that it illuminates.

To envision how beam distance is tested, imagine a headlamp with fresh batteries attached to a fixed position. It is switched on, placed on its highest mode, and a light meter (technically known as a lux meter) is moved further and further until the meter, measuring the center of the headlamp's beam, registers 0.25 lux. That is a headlamp's maximum beam distance (which slowly grows progressively shorter as batteries are drained). This number is usually prominently displayed somewhere on packaging. Some brands also display beam distance numbers for lower-intensity settings

Run Time: 9~12 hours (not at 5 watt high power output)
•Reported in hours (for example, 50h, meaning 50 hours).
•Determined when batteries (the same type sold with the headlamp) are new.
That would leave a number of high-powered headlamps with a lot of energy still in the tank—still possessing enough battery power to project usable light (the light of a full moon). A high-intensity beacon such as the Peztl Ultra (rated at a dizzying 350 lumens) would still have a very serviceable 35 lumens of light available at 10% of original output.

Since most outdoor adventurers can function safely in an emergency mode with good moonlight, headlamp makers calculate run time until lights can no longer produce usable light (the light of a full moon) at 2 meters. Thus headlamp makers consider a headlamp serviceable if it can project 0.25 lux, the equivalent of a full moon's light, on the terrain in front of an on-the-move adventurer in the dark. It's a legitimate calculation that REI's Quality Assurance Lab endorses. This is usually measured with a lux meter.

Lithium Batteries: 3.6V 4400MAH
Headlamps designed to work with lithium batteries are a good choice for cold-weather usage, since lithium batteries outperform alkaline batteries in cold conditions.

Charging adapter:
AC85~265 input, 500mA/3.6V output. Full charging needs 5~8 hours. Over-charged protect.

•Water resistance: This headlamp are able to withstand exposure to rain and snow. (They can handle modest drops and jolts, too.)  But not for prolonged underwater submersion.
•Tilt: Can the tilt of the headlamp unit be adjusted up and down? This item is 60 degree adjustable. It's nice to have that option in order to position the beam exactly where you want it. This especially comes into play while reading by headlamp.
•off / High brightness / low brightness switches: Some headlamps switches lock to prevent a headlamp from being inadvertently switched on inside a pack. (That's a nice feature.) If you're examining headlamps at a store and demo models are available, play with the buttons. Do you find them easy to activate? Are they somewhat glove-friendly? Are you content with how the headlamp cycles through its modes? I prefer starting on low, then ascending; others want the brightest mode on first push. Headlamps vary in their approach.