Please note that these specially made duvets do not come with buttons or button holes (4.5 tog has no buttons & 9.0 tog has no button holes) so it is not possible to construct an All-Seasons duvet from them. Hungarian Goose Down is known to be the world's finest duvet filling. Accordingly, the Luxury Hungarian Goose Down Double size Duvet is the choice of the dedicated pleasure-seeker - and second only to our Ultimate Hungarian