Size recommendation: Go one size down from your average shirt size for a super snug fit that sits high up into your waist or go with your shirt size for a little bit more room. Check out the size guide and visual size guide to make sure you are getting your perfect SNUGFIT size! Suitable for pets up to 13 lbs. For pups 13 lbs. to 20lbs. please order The Snuggit Plus+. Snuggle Sac sold separately. * Made from sustainable, cotton linen fabric. * Breathable yet durable carrier holds the weight of your pup comfortably