Teenage Mutant Ninja Turtles Dudes Kids Reversible Single Duvet Cover Bedding Set (Twin Bed) (Multicoloured) Please note: This product is a UK import, the duvet cover supplied is slightly smaller than the standard US duvet size, it will fit but the duvet may fold at the edge when covered. This is not a comforter but a cover for a duvet. Teenage Mutant Ninja Turtles duvet set to fit single bed. Reversible design. Size: Duvet cover 54in x 79in, Pillowcase Size 19in x 30in (all sizes approx).