Our Zack & Zoey Basic Dog T-Shirts are a versatile choice that never goes out of style. Lightweight and comfortable with an elastic neck, sleeves, and hem. Get back to basics with this classic dog t-shirt! Elastic neck, sleeves, and hem provide a comfortable fit. Size XS - Neck - 6-10 inches, Chest - 14-16 inches, Length - 10 inches. Recommended Size by Breed: Australian Terrier, Chihuahua, Pomeranian, Toy Poodle, Yorkshire Terrier. Material: 65% Polyester, 35% Cotton. Sizing Guide Back - Measure the length of your pet's back from the base of the neck to the base of the tail. See below to estimate by breed. Neck - Measure the circumference of your pet's neck for a comfortable fit. There is no need to add inches like you would with a collar. Chest/Girth - Measure the circumference around the fullest part of the chest and add 2 inches. Care: Machine wash cold on gentle cycle. Air dry. Note If the dog has a sturdy build, select a larger size.