Soft Expandable Carry Bag: Size S is 41 x 25 x 23 cm (L x W x H) by extending the 2 mesh windows. This carrier weighs approximately 1kg and is suitable for pets up to 4kg. Suitable for rabbits, chinchillas, ferrets and other small animals. Please check measurements before ordering.Comfortable Space: Extra-large space allows pets to spread out, lie down, see all around and relax when you have a plane trip, also works great in the car, spacious and they lie down like a bed. The bag can be folded completely flat when not in use.Durable Material: Strong metal frame prevents it from folding, soft enough to compress to fit under an airplane seat. Top windows and 2 sides in anti-scratch ventilated mesh. The polypropylene base helps keep all pets in place, with comfortable thick washable and removable plush padding. Well-stitched Oxford fabric ensures long-term use.Multiple ways to carry: self-locking zipper to prevent your pets from escaping. A strap on one side can be slipped around the rolling luggage's extendable handle. Two flexible handles to hold with your hands. Additionally, it provides a longer, removable strap for hanging over the shoulders and has a side pocket for storage.Airline Approved Carrier: Carry On Bags S sizes are approved by airlines, in compliance with standard airline size rules. Bag easy to put under the plane seat when traveling. Regarding the size L, it is better to check the standard size of the corresponding airline (PS: There are two removable fiber rods on both sides of the top of the bag. When the large bag is too high to fit under the seat, you can remove the two fiber optic rods and put it on easily.) Features: Fabric: 600D x 600D Oxford fabric lining, 230D polyester mesh, hexagonal zipper, metal zipper and nylon teeth with a durability of 10,000 uses. Note: All materials are safe for pets. Designs and functions: Multiple mesh designs for good ventilation. The expandable area allows your pet to have more room to move and increase air circulation. The wire frame on both sides supports the stand to make it more sturdy. The woven nylon hand and shoulder strap is strong to carry. Two zippered doors for easy access. Fleece travel mat, comfortable for animals. Side pockets can store small items. Airline Approved Carrier Tips: If you have an aisle seat there will not be enough room to spread out the sides, you need to be seated in the center or seat near the window to enlarge it. Our carry bag is flexible enough to compress 2.5cm or 5cm to fit under an airplane seat. There are slots inside that allow you to remove them easily. You can always put them back later, but if you don't remove them, you'll never be able to push the bag under the seat. Attention: Please check with the airline before traveling to avoid flight problems.