I was checking Amigakit's site, and it says:
"The floppy drive is compatible with various revisions of Amiga motherboards and fits into any standard 3.5" bay."
If your tower isnt a standard 3.5" bay, then obviously wont fit.
This is how an infinitiv tower looks like in the front:

and this is the floppy drive's picture on amiga kit:
