The PhaseOne XT camera body has a lens mount which is compatible with Cambo lens panels.
Here you find the listing of most lens panels that are suitable to work on the PhaseOne XT:
WRA-2035 with Rodenstock 35HR in Aperture Only mount.
WRA-2040 with Rodenstock 40HR in Aperture Only mount.
WRA-2050 with Rodenstock 50HR in Aperture Only mount.
WRA-5105 with Rodenstock 105HR-Macro in Aperture Only mount.
WRA-2138 with Rodenstock 138HR-Float in Aperture Only mount.
WTSA-832 with Rodenstock 32HR in Aperture Only mount in Tilt/Swing panel version.
WTSA-835 with Rodenstock 35HR in Aperture Only mount in Tilt/Swing panel version.
WTSA-840 with Rodenstock 40HR in Aperture Only mount in Tilt/Swing panel version.
WTSA-850 with Rodenstock 50HR in Aperture Only mount in Tilt/Swing panel version.
WTSA-870 with Rodenstock 70HR in Aperture Only mount in Tilt/Swing panel version.
WTSA-892X with Rodenstock 90HR in Aperture Only mount in Tilt/Swing panel version.
WRE-CA for use with Canon lenses such as T/S lenses with larger image circle.
WRS-HV for use with Hasselblad-V lenses.
WRS-M645 for use with Mamiya-645 lenses.
All above lenses have no electronic connection to the XT body and have no transfer of data for aperture setting or exif-data. These lens panel also have no shutters and should be used with the sensor based electronic [rolling] shutter of the IQ4.