The best and safe solution for fearful and stressful dogs.For example, for fear of fireworks, thunderstorms, cars or traveling The Thundershirt is easily put on and ensures a consistent pressure on the core of the dog. This pressure has an enormous calming effect for most dogs. Use the Thundershirt polo for: * Fear of thunderstorms* Fear of cars or traveling * Irritability * Fear of separation * Fear of doghouse * Pulling the leash * Problems with barking * Reactivity * General training tool * Fear of every noise * General fearsomeness What size is right for my dog? ThunderShirt comes in seven different sizes... XXL, XL, L, M, S, XS, and XXS. Click the link below to find the right size for your dog. Like people, dogs come in many different shapes and sizes, so if your dog has unusual proportions, you may need to go up or down a size versus the "standard" measurements. But the ThunderShirt is designed to be very adjustable to accommodate different dog shapes and still be easy to put on. Dog Size - Chest Size -Weight XXS - 23-33 cm - 50 kg Cat Size - Weight M - 4-6 kg L - > 6 kg