Rab Generator

Alpine Jacket £250

+ Warm, packable, hard-wearing, moisture-resistant synthetic fill

- Pricey for a synthetic jacket, no women’s version

This jacket features the latest innovation in synthetic fill, PrimaLoft Gold with Crosscore. Its polyester fibres are infused with aerogel, an ultralight material developed by NASA to insulate space shuttles. The resulting fill is up to 52% warmer than standard PrimaLoft Gold, with performance comparable to 750+ fill power down in terms of warmth for weight and compressibility.

It gives excellent all-round protection and coverage thanks to a roomy hood, drop tail and cinchable cuffs that work well with gloves/mitts. Other features include a zipped outer chest pocket and two zipped handwarmer pockets. Alas, they’re not fleece-lined but are placed high enough to stay out of the way. Inside, two dump pockets are perfect for temporarily stashing gloves or a flask. This ticks plenty of boxes as a warm winter layer for stop-start mountain days.

It also feels pretty tough, thanks to a Pertex Quantum Pro shell. The front of the jacket uses Diamond Fuse fabric, with interlocking yarns for better abrasion resistance compared to standard ripstop nylon. A DWR finish adds water resistance too. For a synthetic jacket, it is also remarkably compressible, comparable in pack size to Jöttnar’s Thorne down jacket.

■ Insulation PrimaLoft Gold Synthetic Insulation with Cross Core (133gsm body / 80gsm hood) containing 74% postconsumer recycled material

■ Shell 20D Pertex Quantum Pro nylon 40gsm (Diamond Fuse front/Recycled back)

■ Sizes: Men’s XS-XXL Women’s n/a

■ Weight 540g (men’s M)