Baksana 80/20 Summer Hungarian Goose Down Feather Duvet Inner. The Hungarian Goose Down is renowned for its superior thermal and insulating properties. This luxurious summer weight duvet inner filled with 80% White Hungarian Goose Down and 20% Feather as per EN 12934. Covered in a 100% pure cotton down proof cover with box construction for an even filling. These duvets are like sleeping under a cloud.