The Touchdog Onesie Lightweight full bodied T-shirt Jumpsuit is composed of soft high thread count polyester, cotton and Lycra. These Pajamas cover the legs and arms for a more expandable fit and comfortable sleep, fabric is also breathable. Features accented print detail along the back with a leash slit along the neck area. Machine washable. Available in Multiple Colors and Sizes. Sizing Guide: From Back of Neck to Tail area ("In" Inches) 8" : EXTRA SMALL 10-12": SMALL 14-16": MEDIUM 18-20": LARGE 22-24": EXTRA LARGE