PS5 controller for size comparison. I work in an animal clinic so I’ve dealt with just about every style of pet carrier you can imagine. I was hesitant to buy any “soft shell” or backpack style carrier for my guinea pigs as I feel most of them are just not sturdy, the zips are horrible to use and they’re overall not worth the money.Well I have to admit, I can see why this one was rated so well. The zips glide so smooth, it’s nice and study, and the “pop up” expansion part doesn’t just fall in on itself (I included a picture of my PS5 controller on top of the mesh expansion part and it’s not bending or caving in at all). It came with these removable base liners that add to the structural integrity and they make for easy mess clean up. The straps move right out of the way for the expansion part to come out, the straps are super adjustable and have a piece that holds the straps in place. The pockets are a fair size, albeit a bit small.I’m really impressed and would recommend for anyone using this for a small animal (rabbit, guinea pigs, chinchillas). I can’t say for sure but I think it would hold up fine for a small dog or cat, I think anything over 4kg would test it’s limits but I’ve not tested it on anything that big or heavy.