95% Cotton/5% Spandex INNOVATIVE DESIGN: Designed by an RN BSN and Nursing team; expands up to 18 months to fit your baby's growing needs, ensuring sound sleep at each milestone; patented design 5 STAGES OF GROWTH: Eliminates the need to purchase several swaddles and wearable baby blankets; grows into 3 multi-sized swaddle variations; further evolves into a large/extra large, arms-free sleeper SELF SOOTHING: Encourages back sleeping and eases the transition from womb to world; the stretchy but snug fit moves "with" the baby, re-creating a womb-like environment and simulating the feeling of being held, touched, and cuddled COMFORTABLE AND BREATHABLE: The cotton/spandex fabric promotes gentle airflow; the design is hip and shoulder friendly; the narrowed waistline gently compresses the tummy, providing additional comfort for your baby EASY TO USE: No origami required, this easy to use one step baby swaddle will not unravel as a blanket can; two-way zipper allows for easy diaper changes