Alfie Pet Apparel - BAMI Diaper Dog Sanitary Pantie 2-Piece Set (for Girl Dogs) Size XS fits waist size 6.5". Measure the waist size before the back legs. Sizing for each dog is unique. We highly recommend you measure your pet precisely with a flexible tape measure to ensure an accurate fit. We recommend one size up for comfort if your dog's measurement is the higher end of the range listed. Eliminates problems from untrained pups, females in season, incontinent dogs and excitable urination. Place adhesive napkin on inside of garment to adsorb liquids. Washable and reusable. Made of nice soft cotton, very comfortable for daily wear.