How to measure - Neck: Measure around your dogs neck leaving room for two fingers. Chest: Most important measurement; measure your dogs chest around the widest part. Add 2 inches for comfort. If your pet falls somewhere between two sizes, we advise ordering the larger of the two. Warm dog coat - Waterproof surface with thick cotton inner, the dog coat is windproof, waterproof, lightweight, durable and warm enough for pet dogs wearing in cold winter days or cool autumn. Multiple sizes available - The dog coat comes in 8 sizes, suitable for dogs from small to large size, non-sticking hair lining,comfortable for dog to wear. Easy to put on and take off - Smooth zipper closure, the high collar of the coat makes dog feel warmer, the neck is also adjustable. Theres harness hook on the neck for safety walking. The coat is machine washable for easy cleaning.