This sleeveless dress is soft, lightweight and versatile for an everyday walk to a special occasion! Fashionably designed, excellent quality made dress with careful attention to detail. Small size will fit your Chihuahua and Medium size will fit your Boston Terrier or other dogs within those size ranges. These dresses include two Velcro connections around the chest and waist that will allow you to adjust the tightness of the fit. Small size neck range is 10" -12" inches and Waist range is 15" - 19" inches. Medium size neck range is 15" – 16" inches and waist range is 20" – 25" inches. Please make sure to measure your pets neck circumference and waist line before selecting the size.