This is a Conklin Endura Nozac Symetrik Jet Black piston filler fountain pen c1931. The Symetrik was the streamlined part of the Endura line in the 1930-1931 catalog and bears the gold filled Crescent inlay in the cap. This Nozac model is essentially a piston fill Symetrik. This way Conklin could trade on the Endura quality image and the Symetrik shape with this new model. This 5 1/8 inch long pen has barrel stampings "Trade Conklin Mark, Toledo. Ohio. U. S. A., ENDURA NOZAC, SYMETRIK" on one side of the barrel and "PAT PENDING" on the other side. It has the April 28, 1918 patented Conklin clip. It uses the 14 karat gold Conklin Endura nib.