Upgrade your older NN3 with the new rotator for the NN3 MKII. This consists of only 2 pieces - upper tension knob and lower rotator knob with spring ball, 1/4-3/8 screw adapter.
Greater precision, easier use of handling, rubberized edges, no lock screw, this is certainly a must have!
Existing NN3 detent rings from the MK-I will work with the MKII.