Size medium 13-19 lbs From site • Gentler way to help your baby transition from swaddling to arms-free sleep with patented zip-off wings. • Converts to a snug sleeping bag, maintaining the secure feeling of being swaddled. • Twin zipper for easy diaper changes. • Easy Care: machine wash on gentle, tumble dry on low. • 1.0 TOG fabric is ideal for moderate room temperatures between 68°F and 75°F • Certified 'hip-healthy' by the International Hip Dysplasia Institute allows recommended flexion for hips & legs.