Epson Progression 4 User Manual page 98

To insert a diskette drive, align the guiderails on each side of
5.
the drive with the notches on each side of the drive bay and
slide the drive into the bay as far as it will go, as shown
below. Secure the guiderails to the computer case with the
two retaining screws.
notch
guiderail
3-22 Installing and Removing Drives