Sub Zero – Lightweight Thermal Down Jacket

Three hundred grammes. That’s the weight of my wallet and iPhone combined. The two things, along with my keys, that I carry everywhere, regardless of outfit, weather and circumstance. I don’t even feel them any more, such is their familiarity in my pockets, and it’s not like they weigh an awful lot.

In fact, they weight exactly the same as the Sub Zero Thermal Down Jacket, which considering its size, must surely be filled with helium. It’s extraordinarily lightweight, and yet with a fill power of 800+ goose down it is extraordinarily warm too.

Snuggly like a sleeping bag

I went for a walk this morning in a T-shirt and this jacket. The temperature is 7C and I was, at times, so warm in the jacket that I needed to take it off. It’s like a sleeping bag, trapping huge amounts of air inside its 3-4cm thick down chambers and closely-fitting the body to seal in all your body warmth. It doesn’t make sense that something so light could be so warm – the mind naturally equates weight with insulation – and yet it is.

The external shell material is a 100% Polyamide and extremely thin. It feels like it would rip at the merest snag, but having worn it through a few woodlands it is much tougher than it looks. The only change to this material is the addition of a warm fleece material on the neck, which doesn’t rub or get sweaty and helps trap air from escaping upwards.

The main zipper is a chunky YKK number with an effective chin guard and nice positive action. It has a wind-baffle behind it to seal out the breezes. The cuffs are elasticated, and the waist has a bungee drawstring to keep the wind from chilling you. You get two zippered hand pockets which are perfect for doubling the weight of things with your phone and wallet!

It’s not sold as waterproof, but it has survived a couple of short-sharp showers admirably, which was a pleasant surprise. I suspect that this is due to the extremely dense nature of the shell fibre, rather than any treatment.

The jacket lacks a hood, which keeps the weight down but means you’ll need to match it with a hat on the chilliest days. Sub Zero make a range of good hats, so that’s no bother.

And lastly, as a hint on how the jacket could be used, Sub Zero supply it with a small drawstring bag so it can be stuffed down and carried in a pack until it’s needed when the weather gets cold.

A brief bit of research (with emphasis on the ‘brief’) suggests that the Sub Zero Down Jacket is the lightest in its class, and has one of the highest fill power ratings. Certainly, when compared to the North Face Nuptse jacket, which is considered a classic Down jacket, it has a higher rating and comes in at under half the weight.

SUMMARY: I don’t think I’ve ever experienced a jacket this warm AND this light before. It’s had a lot of use over this winter both by myself and the wife and is now a firm favourite in our house. A brilliant piece of gear for cold days.

 Price: £129 rrp
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