S size, neck circumference 34cm, bust circumference 37-48cm, recommended weight 7-6kg, M size, neck circumference 39cm, bust circumference 46-54cm, recommended weight 12-9kg, L size, neck circumference 45cm, bust circumference 52-60m, recommended weight 18-12.5 kg, XL size, neck circumference 51cm, bust circumference 60-70cm, recommended weight 25-19kg, How to cool down soak the dog cooling vest in cold water before going outside, and wring out the water while you wear it. If you think it is not cool enough, you can put it in the fridge for 10 minutes to get the cool feeling, and then put it on immediately. Cooling fabric made of safe, non-irritating cooling fabric, this cooling vest for dogs is lightweight, breathable and comfortable to wear. This coolant dog clothing regulates the temperature by absorbing heat through quick evaporation and it can give your pet a cool, cosy feeling. High safety: the reflective strips of the dog safety vest can protect your dog while your dog goes out at night, even the D-ring of the harness can greatly limit your dog's freedom of movement to ensure the safety of your dog. Perfect fit the sides of the cooling coat for dogs have a hidden socket design, which is practical and aesthetically appealing. The cooling dog vest has a belt buckle that allows you to adjust the chest cage for a better fit. The adjustable neckline ensures a comfortable, high-performance fit that is easy to put on and take off. Evaporative cooling principle: the dog vest has a 3-layer construction. The outer layer reflects sunlight and promotes evaporation, the middle layer absorbs and retains moisture for evaporation, while the inner layer is waterproof yet transfers the cool feeling to the skin.