anybody tried this swedish milsurp sleeping bag?

[Steffen]

it says its a fiber bag, whatever that means.
and its 200cm long, 80cm zipper and weighs about 4kg

i'm thinking of having it at home in case of a wintertime power outage.
(i don't have any other means of heating)
size and weight is not a concern, but it needs to be warm.

if anybody has tried one, do you think it would be suitable for my use

 

[brambles]

From the limited view in the pic it looks like one of the Carinthia Defence variants