We were uncertain with how it'd go at first, but figured we wouldn't know until we try! SO glad we did! We got our kitty from Second Chance for Homeless pets, and they said she's been around humans but was never truly an indoor cat at any point in her life thus far. When we adopted her, we decided/agreed to have her be an indoor only kitty but wanted to give her that freedom to go outside occasionally!

*** ABOUT TRAINING OUR CAT TO USE THE HARNESS ***
She's one year old, and this is what we did to get her into her harness and outside!....

For about a month we put the harness on her gently while feeding her maybe 2-4 little tiny treats letting her know it's OK. She protested a little bit at first, but she's never been the least bit hostile, so we weren't concerned about that at least! She'd just sit there/lay down and not move. We left the harness on her for 10-30 minutes at a time (after about 3 weeks we left it on for a full hour!), and would then take it off her and give her plenty of praise and maybe another treat or two...
Each week we noticed an improvement! The first week she just laid around in it and didn't move much.
After a while she started to slowly move around (with such a hilarious/odd walking style...!)
The next week she started walking around more ...normally lol...
The next week she wasn't afraid to run around and play with her toys!

Fast forward to about 5 weeks later and now she sits at the front door and WANTS to go out! She even nuzzled into the harness when I held it up to put it on her. It is SO cute! You just have to know/read your cat's tells to see how best you can harness train them. I think it helped me knowing that it would be a long process. Some people it was fine and dandy in a week, but each cat is different. It took my cat 4-5 weeks to be completely comfortable in it.

She seems to want to go out at night though, she doesn't really like the day time because we live in an apartment complex and the amount of motion and noise outside I think makes her nervous/scared. She'll just walk around our floor and look over the railing, and she's not afraid to go down the stairs or anything, but seems to just enjoy sitting outside for a bit! Amazing purchase, so worth it, and I know she loves it too!

Oh, and we don't really give her treats anymore when using the harness or outside, and she's perfectly fine with the attention and praise, haha.

*** ABOUT THE PURCHASE/PRODUCT ITSELF... ***
We got the S/M size, and she's a ~9 pound Black/Maine Coon/Rag-Doll? mix. She's a tiny thing! It fits her stomach perfectly, without the velcro hanging loose from being too tight/loose or anything. The velcro bit around her neck is a little big though, It'll fit just fine but because it's like...2 inches wide it took quite a bit of getting used to for her. She doesn't like to turn her head in it, she'll just move her body xD...

When I put it on her I make sure to not let her whiskers get caught in any of the neck velcro... and make sure to not make it too tight or too loose. The overall feel of the harness is very comfortable! Nothing irritates her fur or skin as far as I can tell, and she's long haired and none of it bothers her as well. She doesn't get scared of the velcro noise (it's kind of loud...), and it's WAYYYY stronger than I thought! I have to get some form of grip on the harness to actually get it off her. She doesn't mind that anymore either.

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All in all, it just takes some getting used to, a lot of patience, and treats! I attached a photo and I hope it helps... Have fun with your kitties!

Take a look at King Arthur! This is worth the money just to get a laugh at my fat indoor prissy cats face when he stepped on grass the first time. HIS FACE IS SO FUNNY EVERYTIME I PUT HIM IN IT. My big guy is a 4 year old domestic short-hair who is around 17lbs. Because he is so tubby, I thought exercising outdoors would be perfect for my spoiled indoor only cat. For years he has looked longingly outside, chirped at birds, put his paw on the window when the dog went outside...now he can one day roam free. I had to give this a try, for his health and for his obvious desire to be outside.
He -has- slipped out of it twice, but I'm sure it's because it wasn't on tight enough. I'm still finding the right tightness for him. We have a large cleared outdoor space that's fenced for him to do test runs until we figure out the specifics. Right now, he refuses to walk like a normal cat while it's on. He army crawls instead, but I know he is only doing this because he is a drama queen. It's obviously not hurting him (he is vocal about pain so he would meow non stop if it was hurting him,) and it may take another week(s) to get him used to it. Once he figures out he can be outside and run around safely, he will be a happy chunky boy. Until then I get to bask in his ridiculous reactions. Note: some people have said their cats were terrified of the sound the Velcro makes, my cat was not bothered by it at all.
TL;DR fat 17lb cat fits just fine in a size M/L, he hates it because he is spoiled not because it's uncomfortable.

Wanted to take my two large indoor spoiled cats outside and these harnesses work great. I purchased several sizes and find the medium/large one fits the best on both, although it is a little tight on my slightly larger cat of about 18-20 lbs. I tried the XL holster on him which is more comfortable, but when he freaks out he can get himself out of it, only because it is slightly too big for him. I still use it. Velcro strong but my cats really don 't pull or do too much when they go outside. They mostly squat and look around.

I knew when I completed my move from the country to the suburbs that my three-legged cat Mr. Tub Tubs was going to have to transition from an indoor/outdoor cat, to a strictly indoor kitty. Living near a busy road with lots of cars, I didn't want to chance him having another run in with a car and losing another limb. I was worried that he would have a difficult time transitioning, but at first, he seemed to be loving the heating and air conditioning. I noticed however once spring time hit and we had the windows of the house open, he was becoming increasingly desperate to go explore outside. I started by allowing him to spend time out on our second story deck, but quickly realized that wasn't going to work in the long term because he kept trying to dive bomb off the side. I did some research on options for harnessing cats, but was worried that a traditional small dog harness could be easily escaped from. I also read many reviews on other "cat harnesses" that talked about their feline companions escaping and running off. This was definitely something I wanted to avoid considering we were in a new scary place with lots of cars, children, and new sounds he had never heard. I loved the idea of the Kitty Holster because it could be loosened and tightened with ease by the use of sturdy Velcro. I also liked the fact that it was similar to a vest, which reminded me of the thunder jackets you see at pet stores to help keep animals calm and make them feel safe. As soon as the Kitty Holster arrived, I immediately wanted to try it out. I've read horror stories about cats freezing up and refusing to walk so I wanted to see how he would do. *Please note that Mr. Tub Tubs is an extremely friendly, easy going kitty who acts more like a dog than a cat! If your cat is skiddish, this product may not work for you!* I strapped the vest on him, and he didn't really seem to care; he was more curious about the leash I attached to the ring on the back and wanted to play with it. However I yelled for him at the front door and he came sprinting; I think he knew he was going to get to go outside. We sat out on the porch for a good 20 minutes and let him explore the flower beds and newly planted bushes. We also allowed him to explore the dirt where our sod would soon be planted before it began raining. He did have a mini "freak out" when some kids came by on their scooters because they were making noise, and he wasn't real crazy about the cars, but he did pretty well considering he was in a new place, with new sounds and smells. He really can only stand the vest for about 30 minutes or so before he's ready to take it off, so we try and allow him to go outside for short amounts of time in the evening. We also occasionally take him on short car rides to the ball field trying to get him used to traveling. Overall i'm extremely happy with the quality of the vest, as well as its stability. My main concern was that the Velcro closures would hold up if he took of sprinting because he was scared, which he has, and it did! I would definitely recommend this Holster to anyone who wanted to try taking their cat outside, simply for the fact that it will keep kitty safe and secure inside in the event of a scare.

This harness is wonderful! It's super easy to put on and take off and is very secure. My cat adjusted to it rapidly, probably in a matter of 5 minutes or so. He was an outside cat but after two incidents of being attacked by other animals, I've been forced to keep him indoors. This harness is now a great key to his happiness. I'm able to take him out and walk him daily and he's such a happy boy!
There's been a couple of times where something outside startled him and he bolted but the harness held extremely well and with the way it's made there was no choking, etc when he yanked hard against it.
It's very lightweight and durable. I can't say enough good things about this harness!
The ONLY drawback I see to it is that the collar area is a little high but perhaps there's some reason for this because the makers clearly seem to have thought of everything. I would recommend this kitty harness to anyone who has a cat they love.
Photo... Morris happily rolling around in the sun!