Floppy Drive Emulator?

[Sirgeorge]

Does anyone know what floppy drive emulators are good for? I was looking for an internal 5.25 inch floppy drive device for 3.25 inch floppies that connects to sata when I stumbled upon these little puppies. Don't know what they do and can't find much info on them that satisfies my itch. Also, if you could help me find an internal 3.25 inch floppy drive for a 5.25 inch bay that connects with sata or some other modern connector that would be great. Yes I know external drives exist. It doesn't fit my needs.

[mariushm]

Phil from Phil's Computer Lab uses this one, Gotek USB Floppy Emulator :

 

I'm not sure if it's the best out there or most compatible with older hardware (if you want to use it with some 286 or 386 machine or something like that), I know there's some more advanced and expensive "industrial" floppy emulators for CNC machines, automated sewing machines, carpet weaving machines  etc etc but I couldn't tell you a specific one.