You can't tell from the description. It says "Fully insulated by 120gm2 wadding", but it doesn't say what the wadding is. There are loads of good synthetic technical insulations available, normally trademarked by brand (Primaloft is a common one), and there are various none synthetic downs available (such as goose down). I would guess that Prologic, who don't actually make clothes (rather they have them made in China), are not using highly technical insulations.
Imo you want to avoid fishing brands.