To assemble the case, you will need 4 x M2x5 screws
If you are using the PCB in a standard numpad config, you will also need to print 3 stablizer which can be screw in place to the PCB using a total of 6 M3 x 5 screws.
After the 3D printed base is assembled, you will need another 4 (or 3) M2 x5 screws to fix the PCB onto the base.