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. If you're looking for a synthetic duvet that won't break the budget, Classic Microfibre Double size Duvet is the one for you. Made just for us, every duvet is guaranteed for a full 10 years of soothing slumber.