This was the only kennel I found that came closest to airline requirements. It is approved by the USDA and IATA. We were on a military move from the states so this a review on the international kennel features and requirements only. Kennel Features: This kennel has 11 plastic bolt holes- This is the only requirement that this kennel does not follow. It came with plastic nuts. Metal nuts and bolts are required now for every flight. This carrier has 11 bolt holes plus an additional 4 tie down holes. My airline specifically said that every hole must have a bolt. So we needed 15 metal nuts and screws for the carrier. Some airlines let you leave the 4 tie down holes empty but check to be sure and order the bolts ahead of time to get the right amount. We dind't do this and had to buy 3 kits because of shipping time limits. Metal bolts on amazon did not have prime option. But these are what you need Pet Carrier Metal Fasteners Nuts Bolts (1-1/4" Medium Bolts, 16 Pack) 16 pack will ensure a better safe than sorry amount. Has Pre drilled zip tie holes- Hard to find kennels with this already done. It is a requirement to zip tie the kennel doors shut. Quick release are best. Helping Hand Assorted Quick Release Nylon Cable Ties, 8-inch Make sure you insist on zip tying your dogs yourself! I watched the security guy do it wrong and had to redo do it myself. So glad I got the quick release. Same thing happened to a friend only they didn't catch that the attendant only thread it though the hole and not the door. Their dog got loose in the belly of the plane after ripping off the door. This brings me to the next feature. Has single piece metal door- Be sure to follow this guideline, a metal single piece door. No plastic allowed! Some larger kennel doors have a fold in the middle of the door to make packing easier. Some airlines don't specify the type of door needed and some forbid the fold. It gives the dog the ability to pull the door in which will then collapse and allows for escape. This kennel door is a solid one piece. Has protruding bar/side handles- This follows the requirement of "a spacer rim protruding at least 3/4 on all sides with ventilation openings"This is so the airline can carry and move the kennel without using the handle (known to fail on some kennels) and prevent a dog from being able to bite or contact movers hands. This kennel states that the rim is designed to work as side handles. Has 4 sides of air holes- Requirement is air holes must be "on all four sides at least halfway on each side". This kennel has it and even better metal grates! I had a friend whose dog chewed the space between the plastic holes during flight. Some kennels show in the picture that they have air holes in the back but come to find after ordering they didn't have the air holes on the backside in the smaller sizes. Especially for cat carriers. Note- Domestic flights only requires 2 vent sides but they stack and pack kennels like baggage and airflow will be restricted. Go with ventilation on all sides. Food Dishes- These were actually deep enough to be functional. Kennels with dishes attached inside on the walls are not allowed. Airlines must be able to "access dishes attached to door without opening the kennel door" they do this through funnels. On my main international flight with 2 layovers and a total of 20 hours travel they did not feed or water my dogs once. Even though it's the law. My advice freeze water ahead of flight so it doesn't make a mess or even better get a lixit water bottle to ensure your dogs don't dehydrate. We got Lixit Small Dog Water Bottle 16-Ounce Stickers- This kennel came with stickers and that is a requirement but airlines have them and will use their own as well. The stickers included are crap and leave an awful residue. The airlines put the sticker packet of paper work over the " "Live Animal" in 1-inch letters on the crate's top" required sticker. Upon removal of that it lifted the sticker below mucking up the brand new kennels. My advice, bring the stickers and apply at check in where they are needed once the paperwork covers the entire top of kennel and use airline stickers if possible. Note for size- The length requirement for international travel is [their length + half their leg] so there must be ample room in front and back. This made us need the larger kennel which is much larger than our previous kennel. Some will say that the rule of thumb is as long as they can turn around it's okay. But that is the length rule for IATA. Height for IATA includes ears and ears cannot touch top of kennel while standing. Again, why we had to go up a size (dang chihuahuas). After traveling with my pets on over 6 different flights I can say that most airline attendants are clueless about the pet requirements needed. I had one tell me they don't even receive training on the requirements and offered to let both dogs go into one kennel (a international no no). But I did have had one who knew their stuff and used a tape measure. So better safe than sorry! Traveling with your pet no matter how far is stress full. With international flights being long dogs get anxious and try to escape, sometimes successfully in cheep kennels. So get this one! Airlines have different requirements and regulations. It's better to buy new then to try to modify existing kennels. Save yourself the time! Get this kennel and you only need to purchase zip ties (hand release are best), metal bolts, and some puppy pads. I realize this is much more info than necessary for a review but I know how hard it was getting this information. Please check this as helpful so that it may help others in the complicated kennel requirement process. Safe Travels!