The Elephants Snooze Sack provides cozy comfort without loose blankets. It is recommended for babies 3-9 months and 12-18 pounds. The snooze sack's Comfort Vents help keep your baby at a comfortable temperature by providing airflow to relieve excess heat. The Comfort Wraps provide gentle support to tummy to help relieve gas. The bottom-up zipper allows easy access for diaper changing without disturbing baby's sleep. The body is made of 100% cotton. The mesh is 100% polyester. The Comfort Wrap outer material is 100% nylon and the inner material is 100% cotton. Care instructions: close all fasteners including zippers and snaps before washing, do NOT wash with delicate fabrics, machine wash warm inside out with like colors, use only NON-chlorine bleach when needed, tumble dry low, do NOT iron.