The side of the backpack has a nylon mesh, which is breathable. The front of the backpack has two rows of venting holes to increase ventilation. Open bag on both sides: convenient and practical. Breathable space cover, vented hole design, convenient for pets to breathe, see the world. The bag has a smooth double zipper, and the pull is smooth and not stuck. The shoulder strap of the bag can be adjusted to make it convenient and practical.