MaruPet Winter Waterproof Windproof Reversible Dog Vest Coat Warm for Cold Weather Down Jacket Small Medium Dogs (Not Suitable Big Dogs) Y-1-rounds XS XS(Back:9.0'', Chest:13.5'', 3.0-5.0lbs)

• Back-XXS:7.0"/19cm, XS:9.0"/24cm, S:11.0"/29cm, M:12.5"/34cm, L:15.5"/40cm Chest-XXS:11.0"/28cm, XS:12.5"/33cm, S:16.5"/42cm, M:18.0"/46cm, M:20.5"/53cm Neck-XXS:7.0"/20cm, XS:9.0"/24cm, S:10.5/28cm, M:12.0"/32cm, L:14.5"/38cm This vest is Only designed for Small Dogs, Not suitable for Medium and Large Dogs, please pay special attention before you place a order because your carefully choice will avoid plenty of inconvenience of returns. And for security reason, please don't match the leash with the leash ring directly such as arossing the road etc Take each measurement a bit loosely and if any of the measurements are "between" two sizes, or your dog is still growing, Larger size is recommended. Besides, Different manufacturers have different size defination, so the measurements given in a size Medium by manufacturer "A" will be a size Small in manufacturer B's size chart. Don't buy a particular size because that is what you always buy in a pet shop or online store, look at the size chart for Chest and Body and confirm the size before buy