The Breeze Sleeping Bag Liner is available in mummy and rectangular versions. The stretch-knit fabric combines 70% Coolmax Ecomade and 30% biobased Tencel Lyocell fibers to wick moisture and enhance comfort. The mummy version stretches to fit any sleeping bag shape. The rectangular model includes a built-in pillow sleeve to fit an Aeros Pillow. It provides a hygienic sleep environment suitable for outdoor use.