Recommended for 3.5LB Small Dog & Cat 12LB - The pet carrier is specially designed to carry small and medium dogs. You can refer to the size chart in the picture before purchasing to choose the right size according to your pet's measurement size. Comfortable & Safe - Side zipper and Velcro provide double protection, and a built-in safety hook can be attached to your pet's collar to preventaccidental falls. Elastic neck design, the leg and tail openings are designed with soft wrap-around edges to make your pet more comfortable. Durable & Breathable Material - Our dog backpack are made of canvas material, which is lightweight, soft and wear-resistant and not easy to tear and break. Breathable mesh material keeps your pet cooler and more comfortable. How to Use - 1. Untie the zipper and Velcro on one side, and pass the pet's limbs and tail through the hole. 2. After wearing, zip it up and fasten the Velcro. 3. Adjust the shoulder straps to a comfortable position 4. Insert the buckle. Fast and easy to wear, and pet carrier can be worn on your front side or your backside. Wide Application - This dog carrier backpack is lightweight and portable, it can help you easily carry your pet to the outdoors, biking, hiking, camping, going out for a walk or meeting friends, etc. You can also take many interesting photos to share with your friends. In addition, you can use this backpack to keep them still, which makes clipping nails easier.