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