Size:Twin/Twin XL ï¾ |ï¾ Color:Navy Pipeline is a casual duvet cover that offers a bit of an urban feel. The navy blue is pieced with khaki, teal, and green micro-fiber. There is added twill tape details, along with top stitching that adds design and value. The reverse of the duvet cover is a solid navy blue color. One decorative pillow is also included in the set. A duvet cover is a protective cover for your comforter, most likely for your down comforter. Sometimes it?ï¾ï¾s referred to as a comforter cover. Duvet covers are not filled. It has an opening where you can insert your comforter. Filler not included.