Unlike Traditional Swaddles Which Keep A Baby'S Arms By Their Side Or Across Their Chest, The Arms Up Tm Design Of Swaddle Uptm, Allows Your Baby To Safely Bring Their Hands To Their Mouth For True Self- Soothingtm Which Means More Sleep For The Whole Family. Swaddle Up Original 93% Cotton, 7% Elastane 1.0 Tog Fabric Is Ideal For Moderate Climates Available In 3 Sizes: Newborn, Small & Medium Twin Zipper For Easy Nappy Changes Certified ‘Hip-Healthy’ Design Allows The Recommended Flexion For Hips & Legs