Minimally seamed overlay panel across upper body, shoulders and upper sleeve for added weather protection Best uses: winter hillwalking, winter country walking; trekking; climbing; mountaineering; urban use. Stuffed with 650+ FP down (certified by the Responsible Down Standard but at the upper end of what we’d class as ‘entry-level’ in terms of fill power) the Janhukot tips the scales at 800g, so it’s no lightweight. It’s also pretty chunky, with large baffles and a fairly boxy silhouette. You’d struggle to wear it under a shell, so this is certainly not intended to work as a midlayer. Instead, it’s designed as a standalone barrier against the cold. And in that regard, it does a very good job. Indeed, its sheer heft makes it feel extremely cosy.

But that's not quite the end of the story, because fill weight is important too… What is fill weight? Insulation:800FP European Goose Down with Nikwax Fluorocarbon-Free Hydrophobic Finish (250g / 8.8oz, Size M)

Extreme winter conditions: winter and alpine mountaineering, high altitude climbing, polar expeditions Surrounding all this luxurious insulation is the new 13D Gore-Tex Infinium Windstopper membrane. This new membrane provides complete wind-proofing, high levels of breathability and excellent weather resistance. Technically this membrane isn't 100% waterproof, but in practice we've found that only prolonged torrential rain will eventually seep through.