Founded by the climber and caver Fernand Petzl in the 1960s and based in the mountain Mecca of Grenoble in France, Petzl is one of the best-respected manufacturers of headtorches in the world. They make other climbing equipment too of course, including ice axes, ropes and climbing helmets, but it’s for their lights that they are particularly known.

Take a closer look at the Nao+ headtorch and it’s easy to see why. This is, quite simply, one of the most advanced headtorches ever made. Based on their previous Nao model, this features an improved spec, with a lighting power of 750 lumens, compared to 575 previously. It also carries over the cleverest feature of the Nao, Petzl’s patented Reactive Lighting technology.

“This is, quite simply, one of the most advanced headtorches ever made.”

This means that the headtorch automatically assesses the amount of light in your environment and adjusts the beam accordingly. If you’re out trail-running at dusk and your route takes you into a darkened forest, the light will get brighter. Emerge from the woods and it will change again. The changes are so seamless they’re almost unnoticeable but if you look down at a map or a reflective surface, you’ll notice the difference – there’s no glare.

Reactive Lighting doesn’t just make map-reading easier on the eyes, it also means you only use as much light as you need, helping preserve the Petzl Nao+’s battery life. The brand claims that this will last for six and a half hours on maximum setting and up to 15 hours on the more conservative “max autonomy” mode.

While the Reactive Lighting is automatic, things get more customisable with the Petzl app. Pair the Nao+ with your smartphone and you can select from a number of pre-set lighting profiles designed for different activities – hiking, mountain biking, trail running etc. You can tweak these as you like, or set up your own user-specific profiles.