Super soft Organic footie pajama features two-way zipper for easy diaper changes, a cute bum flap for a quick diaper check, and option for open toes when baby is mobile. Fabric: 70% Viscose from Bamboo/30% Organic Cotton Care: Machine wash on low or delicate. Dry on gentle/low or line dry. PLEASE NOTE: NB-6m only include integrated mitts with signature black and white pattern to boost brain development and 6m+ includes reinforced moto knees. Size Chart: Age Weight (LBS) Height (IN) Preemie 3-6 lbs 15-17 in. Newborn 5-8 lbs 17-19 in. 0-3 Months 8-12 lbs 19-23 in. 3-6 Months 12-17 lbs 24-26 in. 6-9 Months 18-21 lbs 26-28 in. 9-12 Months 21-23 lbs 28-30 in. 12-18 Months 23-26 lbs 29-31 in. 18-24 Months 26-28 lbs 31-33 in