An ultralight windbreaker that rolls up to the size of a small apple, the Binary is a useful addition to any outdoor wardrobe.

With a standard-to-slim fit, and pack and climbing harness-compatible design, it provides lightweight protection and comfort for rock climbing, mountaineering and tramping. Over the time I used it, the jacket proved itself suitable for walking, cycling and anytime a lightweight windbreaker was required.

It’s a simple full-zip jacket weighing around 91g and made from light, but very tough 10-denier nylon ripstop with a high-tenacity 20-denier weave on the arms, hood and shoulders. You wouldn’t want to be climbing chimneys or wide cracks in it, but for most normal use the fabric holds up fine. I liked the addition of a hood; in exposed situations being able to cover your head and neck, even with thin layers, can make a big difference to your warmth. Simple elastic cinch cuffs keep the sleeves out of the way and a single breast pocket doubles as a stash bag which can be clipped to your harness.

The jacket fabric is a tight weave, with no laminated coatings, allowing breathability and sufficiently blocking moderate wind and repelling a light shower, but in heavier precipitation you would soon get wet.

It would be useful if the hood could be cinched after rolling it up, but that’s the only flaw I could find in an otherwise well considered product.