Sizing:Small/Medium: 0-3 months, 7-14 Pounds, up to 26 inchesLarge: 3-6 months, 14-18 pounds, up to 30 inchesDiscover the calming benefits of swaddlingBy recreating the secure and cozy feeling of mommy's womb, Comfy Cubs Swaddle Blankets for newborns trigger the relaxation mechanism in your baby so he can enjoy more restful sleep. Bundled snugly in our baby sleep sack and free from involuntary reflexes that would startle him awake, your child will fall asleep more easily and remain asleep longer. Not only will your baby benefit from more sleep during his most formative days, but you'll relax and enjoy watching him grow and develop.A comfortable baby is a happy babyComfy Cubs Swaddle Blankets are made of 100% cotton so they're breathable and thermo-regulating.