This is a Conklin Nozac Penline in the rounded style, 5 inches long c1936. The Nozac Penline was introduced in 1936 and came in rounded and faceted versions. Nozac pens use a piston filling system Conklin introduced in 1931. The pen fills by twisting the end cap while the nib is in ink. The ink level could be seen in the translucent barrel. They were offered in red pearl, green pearl and gray pearl with the new 1935 patented clip and had 14 karat gold nibs. Medium size Nozac Penline pens like this one sold for $5.00 and the matching pencil was $3.50.