My dog was 15 when she lost use of her rear legs, so it has been an adjust for her. She has rear leg movement, but not enough control or strength to stand or walk with them. Photo attached is her on a walk in the park. I take her for one or two walks per day totaling about a mile on a leash per day. She is in the chair a couple other times to go to the bathroom in the yard or get a drink of water. About 2 hours in the wheelchair total per day. I have a lot of complaints listed below - My goal is to show buyers how to make their chairs safe and hopefully get the manufacturer's attention to remedy some serious issues before dogs get injured. I have a lot of complaints here, but this is very likely still the best one out there despite having some serious and often dangerous flaws.The good:- It is pretty sturdy and not very heavy.- Lots of adjustability.- Rear cradle for hips is well padded and leaves no red irritation on her. (There is an alternative rear cradle that they sell, but it is little more than a female dog pee catcher or male dog rash giver. Really poor design on that alternative but it can be modified easily to resolve those issues. )- She can freely pee/poop without getting anything on the chair or her legs.- When excited, she can easily run over objects 8 inches high such as curbs, twigs, dirt bumps, small dogs, feet, etc.The bad:- The nuts on the wheel bolts stick out too far and are constantly catching or scraping on things.- They need more wheel size options. Mine came with 12 inch wheels, but my dog is old and very hesitant on grass or uneven terrain. A 16 or larger inch tire option that smooths out bumps in terrain better would be ideal for her (although it will cause more roll-overs, but that's a fair trade-off). I ordered larger lightweight wheels from SmallTiresandWheels dot com (they are also on Amazon, but shipping is less on their website) and may update my review after I put them on.- Unless your dog has complete paralysis of the rear legs, the stirrups included are worthless. My dog twitches her legs and the stirrups would never stay tight and would always result in her feet dragging on the ground. Worse yet, the pad would always shift to the side and there would be a thin rope rubbing directly against her fur. I ended up using old socks and metal ties to hold her legs up. Zip ties would work well for anyone trying to reproduce with I did.- The nylon straps will not stay tight. They always loosen up. Probably using an improperly thin nylon for their attachment hardware. I have knots in places and clothes snaps to keep things tight.The bad safety issues:- The rear over-the-hips straps to keep your dog in if they tip over are poorly designed and way too long. With the straps in place in the X formation, my dog fell completely out of the rear of the wheelchair when she fell over. I have a skinny dog with long legs and there was at least an extra foot on the straps that should have been cut off. There is no adjustability to make them shorter and I ended up cutting them off completely and using a custom velcro strap instead to hold her back from falling out in a tip-over.- The harness clasp is designed to pull apart with moderate tension applied. This can cause the harness to come undone and your dog can fall out and possibly twist or break their rear legs or spine. Very dangerous. This clip failed on me multiple ltimes when I lifted the wheelchair plus dog to go through a doorway. She immediately fell out of the front with her rear legs trapped. Luckily, she was uninjured. To fix this, I used a file to add a positive engagement angle on the clips and they have never come undone since. Also, having the clip on the top rather than the bottom (red strap up) will reduce the potential for failure.- The safety caps on the front that protect the sharp edges of the aluminum are simultaneously oversized and not well secured. The result is that they almost always fall off if you remove the harness. Really bad design and tolerances as seen in the multiple customer photos where almost no users of the wheelchair have the caps anymore. Recommend the manufacturer get a better fitting cap that doesn't get hung up on the harness and has a positive attachment like a screw to keep them in place. Without the caps, your dog could easily injure your ankles, another dog, or possibly themselves if they tip over with the sharp metal end exposed.- No padding on the metal parts. Rollovers are common and when your dog has spinal damage like mine, having her land on a thin metal bar is dangerous. She was constantly complaining about soreness by her shoulders until I added padding.- No reflectors. There are no reflective surfaces, paints, or tapes on the unit. This makes nighttime walking dangerous. I added some DOT tape scraps to mine, but this should be included from the manufacturer as this is literally pennies in additional cost on a $500 item.Summary of my modifications:- Added rear-pull leash mount using clothesline, crimp connectors, and heat shrink for safety. Allows her about 90 degrees of right/left freedom while we are on a walk. Helps her psychologically by providing a gentle pull from the rear to get up hills, over large bumps, etc. This setup requires great care as it is very easy to tip your dog over if you pull at them sideways.- Added reflective tape for night-time walks- Added poop bag holder- 3/4 inch foam padding on horizontal rails to lessen impact of tipping over. https://www.amazon.com/gp/product/B07PXSHJF6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1- - Used a silicone tape over the foam where I pick her up to avoid getting glue on my hands.- Flipped the harness upside-down (now red strap with buckle is now on top). I put her rear legs in the X holder and have her step into the front harness that stays attached to the chair at all times. Once stepped in, I lift the front harness and clip the red strap's buckle into place.- Buckle on red strap would pull apart when lifting the dog in the wheelchair. That's why I originally flipped it over. With a small file, you can add a small angle to the attachment points to make it much stronger.- Socks for foot holders. They are cheap, washable, and work 1000% better than the stirrups that came with the kit. I have metal loops holding the socks up, but zip ties will work just fine.Future mods:- Larger wheels (not installed yet)- Laser engrave contact infoSummary of recommendations to the manufacturer:- Shorter wheel bolt and low profile locking nut OR offset hub wheel to prevent snagging the nut on things.- Add reflectors- Add a leash attachment option. The one I created pulls from the rear and gives the dog about 90 degrees of left/right freedom. Great for old dogs that need a little extra assistance without dragging them around.- Larger wheel options- Personalization like laser name engraving.- Redesign the rear leg stirrups to allow the feet to slot into them (like a sock).- Redesign the over the hips safety restraint. It is useless as designed. A simple over the back belt would be much better.- Get better nylon webbing latches. The current ones pop apart very easily.- Make sure you use nylon webbing that is compatible with your hardware. The current combo do not hold well and are constantly loosening up. Likely too thin of nylon webbing.