Fox & Finch Baby Front Zip sleeping / pram bag It has a double zip which is a very useful feature with these sleeping bags. The bags have a slit in the lower bottom of the bag at the back, which enables it to be worn by a baby and still allow access for pram straps/car seat straps without having to remove baby from the sleeping bag. The shell of the sleeping bag is made from 100% cotton. The inner lining is made from 100% cotton. Soft and comfy.