2.5" drives come in a variety of thicknesses. The standard thickness is 9.5 mm, but there are also 5, 7, and 12.5 mm. 5 and 12.5 are very uncommon, but 7 mm is somewhat common. And no, I have no idea why drive specs are mixing Imperial and metric units, lol.
I would start by Googling the model of your current drive, which you should be able to find under Device Manager. If you find that it's a 9.5 mm drive, you're good to go because that's the easiest of all. If it's a 7 mm drive, the next step would be to open up your system and determine whether it just happens to use a 7 mm drive or whether that's the thickest drive that will fit. Some systems in the former category have 7 mm drives installed in brackets designed for 9.5 mm drives and use bumpers or foam to fill the gap so that the drive's SATA connector lines up with the motherboard's. In that case, you'd have to choose between either finding a 7 mm SSD or buying a standard 9.5 mm SSD and removing the foam/bumpers since you won't need those. If you have a 5 mm drive and that's all your system will accept, I don't know of any SSDs of that thickness, but then again I haven't looked for them either.
2.5" hard drives come in multiple heights - just about every 2.5" SSD is 7mm, which is the size this system takes.
Just about any 2.5" SSD will fit and work. There are advantages to the top tier of manufacturers (Samsung, WD/Sandisk, Intel, Crucial/Micron) over lower-tier manufacturers - reliability and quality being among those.