Despite an extensive line of products, it could be argued Petzl is only known for one thing––headlamps. Trusted by the most discerning cavers, climbers, rescue teams, and backcountry enthusiasts, Petzl headlamps are the standard by which other lamps are measured. The Petzl NAO, which has been exhaustively tested in the field and is in its second year of production, is quite easily the most sophisticated headlamp ever to cut through the inky black of night. Pun intended, it's simply brilliant.
The NAO produces an eyeball searing 355 lumens from its twin LEDs, but that's not what makes this lamp so remarkable. What makes the NAO unique is its freakish ability to automatically adjust light output to meet the user's changing needs; Petzl calls it reactive lighting. When reading maps or doing work at arm's length, the NAO's sensors measure ambient light levels and not only widens the light pattern but immediately reduces output to save battery power and minimize harsh light conditions. Point the NAO into the open darkness and the beam narrows and the light output increases to the full 355 lumens. It just knows how much light you need at any given time. In theory it sounds convenient, but in practice it works better than expected, and maybe better than it should for such a new product. The NAO can even be interfaced with a computer to customize the reactive light settings.
More than just a bright light in every sense of the word, the NAO is a full featured lamp with several design elements that warrant recognition. The USB rechargable Lithium-ion battery can be cycled 300 times and provides nearly 5 hours of run time at the maximum setting. That in itself is impressive, but at only 108 grams, the battery is light as a feather and barely noticeable with it's position at the back of the user's head. The power switch has a locking mechanism to prevent the light from powering on when not intended, and the adjustable headband is designed for optimal adjustibility and comfort. The entire package is water resistant, compact and backed by Petzl's three year warranty. With this lamp, Petzl has outdone themselves once again. It will take some time for the competition to catch up with the NAO.