Dog Diapers Medium: best for dogs and puppies with waist size 13" to 19". Please measure your dog's waist right in front of the back legs to ensure a good fit. NOTE: Don't too tight when measuring. If your dog is in between sizes, factor in their weight. A heavier dog, go up a size. A skinnier dog, go down a size Highly Absorbent: built with multiple absorbent polyester mesh inner layers and waterproof outer layer to prevent leaks and damage to rugs, carpets, upholstered chairs and sofas, carpets, upholstered chairs and sofas Soft and Comfortable: made of soft and comfy material to increase the acceptance, making sure your dog walks comfortably while wearing the diapers; Useful for untrained puppies, female dogs in heat or physiological period, and dogs that suffer from excitement urination or incontinence Adjustable Waistband: built with convenient hook-and-loop closure on the waistband, easy to adjust the length to fit your dog’s waist Washable and Reusable: more economical and environmentally friendly than the disposable dog diapers; Machine Washable and Dryable Avont Washable Female Dog Diapers is designed for untrained puppies, female dogs in heat, and dogs that suffer from excitement urination or incontinence.