I asked them about the two filters in a Canon camera -were they both removed?
The reply from Daniel:
Yes, of course this is how it is done as both filters block IR! However, we still calibrate focus back to the visible spectrum as part of the conversion process so that you can focus accurately through the viewfinder when using a visible bandpass filter.
So, they are doing a FULL full spectrum mod and using a plain clear glass cover to maintain auto focus with standard lenses.