That seller offers two configurations. The one called "Front panel" is for use with electrets like most 25mm capsules. These do not require polarization voltage. The second offering is "Front panel plus polarized panel" which I presume is the basic amplifier and a second board which generates the polarization voltage (60 or 120V) needed by non-electret, so-called "true condenser" capsules like most 34mm capsules.
See?
under "DC biased condenser" (your 34mm)
and "Electret condenser" (your 25mm)
The basic board appears to be based on the popular Schoeps circuit. I can't tell from the photo what circuit the polarization board has copied.
