Use the size chart along with the “Measuring Your Dog” size guide. The back length is the most important for apparel, measure from the WITHERS not the collar. Size 18 inch color Blackberry he Expedition Parka Color Blackberry (other images shown for illustration purposes) is an excellent choice for small and big adventures in cold weather. The Expedition Parka has been especially developed for short-haired dogs and dogs without undercoat, but in cold conditions it is suitable for all other dogs as well. It is suitable for extra warmth, for example, for agility dogs after workouts or for dogs needing warmth due to their age or health. The technical surface material of the easy-to-use coat is excellent for even the toughest of conditions. The Expedition Parka is designed to allow for extended range of motion when the dog is running and playing. The water- and windproof soft elastic segments on the front are flexible with the dog's movements. The neckline, length of the back and the collar circumference of the Expedition Parka can be adjusted. Both the lining and surface fabric are certified to be safe and free of harmful substances in accordance with the Oko- Tex-standard 100. Made with fluorocarbon-free Rudolf ECO water-repellent treatment. Waterproof, laminated fabric Taped seams Adjustable back length, neck and chest In addition to the basic sizes 20-80, there are sizes 40XS and 45XS for Dachshunds and 30XL and 35XL for small, bull-type dogs Please be sure to take proper measurements of your dog to find the best fit. Although some of our products are adjustable, starting with the proper measurements is a must. Back length is the most important measurement for coats, and chest girth is most important for harnesses. We will gladly accept returns of items in new, re-sellable condition within 30 days from the delivery date. We recommend carefully trying on your new products indoors, keeping the packaging intact. Returns must meet the following criteria: · Item is free of dirt, hair, odor, and is in re-sellable, brand new manufacture condition it was received in. · Tags attached and in the same manufacturer packaging.