Size Reference: 3XS - Neck: 5.9", Chest: 9", Back Length: 5.9" (suit for small animal under 1LB); 2XS - Neck: 8.6", Chest: 10.6", Back Length: 7" (suit for small animal animal under 2LB). Since the body size of each small animal is different, please measure your pet's neck & chest circumference and back length before purchasing, and choose the appropriate size to buy. Cozy Pet Clothes for Guinea Pig : This small animal clothes are made of fleece, which is soft and comfortable to the touch, and the openings are wrapped with an extra layer of soft fabric, which is friendly to pets' skin and will not chafe your pet's skin. A Great Choice for Winter and Festivals: small animal clothes are printed with patterns of elk and snowflakes, full of Christmas atmosphere, not only a great choice for Christmas costumes, but also for daily wear, photo shoots, parties, etc., for The festival adds to the atmosphere and makes pets more integrated into the family. Warm Winter: These vest clothes specially designed for small animals can wrap pets in all directions. Keep small animals warm and energized in cold weather. This pet clothes is suitable for most small animals, such as: adult guinea pigs, ferrets, rabbits, bunny, kittens, mini dogs, chihuahua,Yorkshire, chinchilla and other small animals. This pet clothes is suitable for most small animals, such as: adult guinea pigs, ferrets, rabbits, kittens, mini dogs, chinchilla and other small animals.