I custom ordered this bag a few years ago to give the most warmth per gram for cold weather climbing and it exceeded my expectations even providing a good nights sleep bivying at the top of Denali when caught out in awfull weather. Downside of that is that i found it too warm for much else, so had limited use. About 5 weeks in Alaska and a few nights here and there in the Alps in winter.
It's made with 1000 fill down, (read note below) drishell outer, MX inner, draft collar, inside drishell panels around the feet and collar/hood to prevent wetting the down from the inside, side baffles and no zip. Bag is standard length and width and made around their 'lightweight' pattern.
Been stored loosely in a mesh bag away from light and inside out to allow the down to breath freely (because of the drishell outer). It's a bit dirty around the hood draw cord but in perfect condition otherwise.
Postage at cost if required
Note: This was ordered with PHD's top of the range down which they classified as being 900fp. Apparently after I bought it phd moved to the standardised classification and so the down featured in it is now ranked as being 1000 fill https://www.phdesigns.co.uk/testing-down-quality-fillpower