Why does your dog need boots?1. Protect the dog's paws from being scalded in the hot summer.2. Keep your dog's paws warm and dry in the cold winter.3. Prevent dogs from scratching sofas, carpets or wooden floors.4. Keep dog paws clean and dry on rainy days.5. Protect the dog's paws from stones, asphalt, etc. when walking.6. Prevent scratches by dog's nails while playing with dogs.Please follow these easy measuring instructions to ensure a comfortable fit1. Place the paw on a piece of paper and press down on the top,mimicking how the paw spreads when the dog is walking.2. For length mark from the longest toenail to the back of the paw.3. For width mark the widest of the paw left to the right.4. Choose the correct size according to the size chart,the width of the paw should be smaller than the dog shoes size.5. Pet dog might experience some discomfort the first time he wears the pet shoes. You could help him with some simple training.Size ReferenceSize 2: (2.3"x1.6")(L*W)for 26-30 lbsSize 3: (2.4"x1.8")(L*W)for 31-35 lbsSize 4: (2.5"x2.0")(L*W)for 36-40 lbsSize 5: (2.7"x2.2")(L*W)for 40-55 lbsSize 6: (2.9"x2.5")(L*W)for 52-65 lbsSize 7: (3.1"x2.7")(L*W)for 63-75 lbsSize 8: (3.3"x2.9")(L*W)for 74-88 lbsWarm NoteWhile dog boots are waterproof, they cannot be used in deep water or sand, as water or fine sand may seep through the sewing needle holes.Don't worry when your dog starts walking in new shoes but doesn't walk normally or even jumps.You can try to encourage and guide your dog to get used to the new shoes.