Comfort
The Sirocco is modestly comfortable thanks in large part to how incredibly light weight it is. It’s a helmet that is barely noticeable but it also has small, simple padding where it is appreciated, on the top of the head and on the brow. The chin straps are super slim and light, creating a low profile feel and adding to the comfortable fit.

Ventilation
The Sirocco was a popular helmet with testers for its great ventilation and has become one of my favorites for long days in the mountains when I know I’ll be hiking and climbing for hours with a helmet on. Twenty-four slender vent holes wrap around the helmet, from front to back, allowing for good airflow and breathability when you’re working hard.

Ease of Adjustment
The lightweight suspension system features two simple cinches in the rear of the helmet. They take a little getting used to if you’re used to the more common wheel ratcheting systems found on many other helmets but most users grew to appreciate them. Still, they are a little harder to adjust and as you have to be able to release the cinches and then pull the straps to tighten the helmet and they are harder to operate with thick gloves on, such as when ice climbing.

Features
The magnetic chin strap stands out on the Petzl Sirocco as a unique and effective way of securing the helmet. Upon first use, it felt awkward to use but after a little practice users could get it to clip with ease. It is harder to unclip compared to many of the buckles tested as it seems to “catch” and get snagged on the clips. Plus, we experienced some “gunking” up of the magnets over extended use as dirt and sand got stuck to it and on a few occasions the buckle wouldn’t clip securely. Efforts to clean it out completely are difficult because the magnet holds some of that material in place but it was always easy to get enough material cleaned out hold a headlamp in place while remaining relatively streamlined to avoid snags on slings and clothing. Unique compared to other helmets is an elastic cord in a triangle shape in the back that is released and reattached by a small plastic hook. It takes a little more effort to remove and secure a headlamp strap but once in place it holds a headlamp in place better than any other system, aided in part by the lack of a slippery plastic shell like other helmets. For those wanting a visor for ice climbing or mountaineering, two mounting holes will take Petzl’s Vizion visor attachment system.

Versatility
The Sirocco offers great versatility if you’re looking for the lightest helmet you can find, as many people consider when thinking about a helmet for single pitch climbing or for long days in the mountains. The availability of only one color, a bold orange, was a limitation for some as many users considered it an eyesore, particularly for its use in single pitch settings, like sport climbing, where helmets are worn with less frequency. In those cases, many climbers wanted a choice of colors. The option of a visor attachment makes it an attractive option for ice climbers and many trad climbers appreciated the lightweight for those days of lugging gear up a steep talus cone in the desert. But, where we really thought this helmet stood out was in the mountains as it was a favorite when the approach was long or the packs were already heavy with other gear. The lightweight and good ventilation made for comfortable wearing over the course of a long day. Many people expressed durability concerns with the Sirocco because of its absence of a protective plastic shell. Petzl claims that the expanded polypropylene construction negates the need for that plastic shell because it is durable enough. In our experience, it held up as well and better than many other helmets, even when my three little kids threw it, literally, around at the crag. I was even struck by some moderate rock fall while wearing the Sirocco and a baseball sized rock hit the crown of the helmet and left a small indentation but otherwise the foam helmet has remained unscathed after extended use.

Weight
At 165 grams (5.82 ounces – size 2 or large), the Sirocco is the lightest helmet in the world, period. The weight savings is largely due to the one piece construction of the foam helmet that sheds the plastic shell common on other helmets. Thin, light straps and other features also contribute. If, like many climbers in times past, you started with a hard plastic shell helmet like the Petzl Ecrin Roc that tips the scales at over 16 ounces, you’ll marvel at the weight savings on the Sirocco.