Size x small: Neck circumference: 20 cm / 7.9 inches, chest circumference: 28 cm / 11 inches, back length: 18 cm / 7.1 inches. Size small: Neck circumference - 21 cm / 8.3 inches, chest circumference - 32 cm / 12.6 inches, back length - 22 cm / 8.7 inches, size medium: Neck circumference - 24 cm / 9.4 inches, chest circumference - 38 cm / 15 inches, back length - 26 cm / 10.2 inches, size large: Neck circumference - 28 cm / 11 inches, chest circumference - 44 cm / 17.3 inches, back length - 30 cm / 11.8 inches, size X large: Neck circumference - 33 cm / 13 inches, chest circumference - 51 cm / 20.1 inches, back length - 35 cm / 13.8 inches, size XX Large: Neck circumference: 37 cm / 14.6 inches, chest circumference: 59 cm / 23.2 inches, back length: 40 cm / 15.7 inches