These attach in the side 120mm fan slots in the Cooler Master N400 case. They allow two 3.5" drives to be mounted there. They are attached with standard 120mm fan screws. The model Fscrewspacer is included to shorten the mounting screws and prevent them from contacting the drives
The files are different. If you want to mount 2 drives, you'll need one of each.
I used PETG to print these, YMMV
The author marked this model as their own original creation.