What sizes do the duvets come in? Simba - Odyssey March 29, 2018 01:18 Updated Follow We have UK sizes Single, Double, King and Super King available in our Feather and Down Duvet. Related articles What tog level is the duvet? What certifications does the Feather & Down range have? How big is the package it arrives in? Do I need to wait for it to inflate like the mattress? How firm is the pillow? How do I make it go up and down?