The FP170 and the FP230 ports are recomended for the Nikkor 14 mm (114 deg. AoV). The FP120 port for the 10.5 fisheye is too small. I use the FP170-5 (M5) for the Nikkor 12-14 with 40 mm PE and +4 diopter. The "-5" indicates an M5 size port.
I have a FP160-5 dome as it's clearly an M5 port mount.
What lenses are the FP160-5 dome intended for?