What are they made of? Simba - Odyssey November 22, 2017 17:26 Updated Follow Each of these products has a 70% duck feather and 30% duck down filling, lovingly encased in a 100% cotton cover. Related articles What certifications does the Feather & Down range have? How can a pair of Simba Slippers help me? What size is the pillow and will my pillowcase fit? What colours do they come in? Where are these made? Is the down ethically sourced?