At a mere 245g the Cerium LT jacket is a feathery light piece of clothing. That's because it's mainly made of feathers. It consequently packs down into its oblong stuffsack no bigger than a fist. If you're looking for an ultra-packable, minimalist down jacket to act as a stand-alone garment or mid-layer in colder mountain conditions then the Cerium is for you.
Down, of course, comes in many grades, depending on its measured heat-trapping efficiency. The Cerium is stuffed with 850 fill European white goose down, which as you might have guessed from the price tag is one of the very best. This makes it extremely warm for that minimal weight. Combined with a typically astute design by Arc'teryx it's an exceptionally attractive piece of clothing for wild camps and outdoor activities in the colder months.
There are a few surprises along the way. Firstly, the fill is not entirely down. There are also some synthetic sections in areas where moisture might pose a problem (such as the underarms), and there are also no adjustments at all throughout the jacket. The cuffs are elasticated, as is the hem. You'd expect this to lead to some undesirable heat loss, but we've been wearing this jacket for a number of winter seasons now and found the tautness of those openings - and the collar too - to be perfectly judged.
There are two hand pockets and no other storage, but they're very sizeable and placed suitably high up to avoid rucksack belts (not that you're likely to wear a layer this warm whilst in motion). The main zip is extremely small, but has proved remarkably hardy in those same years of use. The jacket version comes without a hood, but £20 more will get you the Hoody version with one fitted.
Downsides? Being down it's very vulnerable to water, unlike its heavy and less packable synthetic competitors.
In conclusion: the price is always going to be a barrier for some, but if you're able to get hold of a Cerium LT jacket you won't be disappointed. It's a premium down jacket that offers tremendous warmth for its weight and packed size.
