S507. Small Bent Needle Nose Pliers.
Michael Sull selected these small pliers, which are ideal for adjusting the flange on an oblique holder. Use them to adjust the curve of the flange to fit the nib you are using, to crimp the two sheets of metal in the curve a bit tighter if necessary, and to adjust the flat part of the flange to reduce the angle of the pen to the paper. They are small enough to fit in your pen pouch or traveling tool kit.