The Pet Life Heavy Knitted Dog Sweater is composed of Soft-Heavy Knitted Cotton. Very comfortable and can be worn any time of year. This pet sweater features a Leash-Slit Holder behind the Neck area. Available in Multiple Sizes and Colors. 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