I didn't need the extra gusset for my floor length dresses, but it does look like it'd be useful for wedding dresses or...um....ball gowns with a big fluffy base? Whatever you're into. Anyway, it's your average cheap "fabric" garment bag. Similar to ones you'd get when you buy a suit or dress from a high end department store. (Maybe starting with N)
I've got 3 dresses on one hanger inside mine right now, and it's keeping them all safe and dirt free. Good length. Plenty of room at the bottom.