Product includes: dress recommended weight: size XS: 1 - 4 pounds size S: 4 - 8 pounds size M: 8 - 13 pounds size L: 13 - 17 pounds size XL: 17 - 25 pounds size XXL: 25 - 32 pounds size 3XL: 32 - 40 pounds measurement: size XS; chest girth: 11.4 - 11.8 inches; back length: 7.5 - 7.9 inches; dress length: 11 inches; neck girth: 7.1 - 7.5 inches size S; chest girth: 13.3 - 13.7 inches; back length: 9 - 9.4 inches; dress length: 12.5 inches; neck girth: 9 - 9.4 inches size M; chest girth: 16.1 - 16.5 inches; back length: 11.2 - 11.6 inches; dress length: 14 inches; neck girth: 10.2 - 10.6 inches size L; chest girth: 18.1 - 18.5 inches; back length: 13 - 13.4 inches; dress length: 16.1 inches; neck girth: 11.8 - 12.2 inches size XL; chest girth: 20.4 - 20.8 inches; back length: 15 - 15.4 inches; dress length: 17.3 inches; neck girth: 12.2 - 12.6 inches size XXL; chest girth: 22.4 - 22.8 inches; back length: 17.1 - 17.5 inches; dress length: 18.9 inches; neck girth: 13.7 - 14.1 inches size 3XL; chest girth: 26.8 - 27.5 inches; back length: 20.9 - 21.3 inches; dress length: 22.8 inches; neck girth: 15.8 - 16.5 inches