From Royer Labs:
In 2002 we introduced the R-122, the world’s first phantom powered, active ribbon microphone. It was a revolutionary development in ribbon mics, combining impedance matching circuitry with condenser-like output levels that allowed the R-122 to be used on even the quietest sound sources. It also allowed the mic to be paired to virtually any preamplifier.
The R-122 MKll takes the R-122 to a whole new level, delivering unprecedented flexibility for ribbons via the addition of a switchable -15 dB pad and a switchable bass-cut filter. The switches are completely out of the circuit when disengaged so when both are off, the microphone is for all purposes an original R-122. The switches are located on the back of the microphone and recessed to prevent accidental activation.