Parker 51 - Vacumatic - Black / Brushed Steel (SB420)
Nib: Medium 14 Kt
Parker 51s are about as reliable as a pen can be. This would be a great pen for daily use. The pen has a new diaphragm, so you get great capacity and a trustworthy filler. The Feather Cap is probably a mis-match from later in the 51's history (seems more Aerometric). The blind cap on the Vac filler has a slight stair-step. Smooth medium nib. 5 1/2", 140 mm.