This is an Eagle Prestige Black in the slimmer size that comes with a 14 karat gold Number 4 nib, c1939. The design was an improvement on bulb fill fountain pens such as the Postal Reservoir Pen. Eagle submitted Benjamin W. Hanle's patent for the design on March 11, 1938 and patent 2,170,242 was awarded on August 22, 1939, which indicates that the Prestige was probably introduced in the 1938 to 1939 timeframe. Inside the translucent barrel is a clear cylindrical ink chamber attached at one end to the nib section and with a short rubber sac at the other. This unit is not flush with the barrel, allowing airflow around the ink chamber through two grommeted holes in opposite sides of the barrel. The pen fills by removing the barrel end cap revealing a paddle-like lever that squeezes the ink sac. These are very uncommon pens that came in two widths, the wider pen with a Number 6 nib and this model with a Number 4, both being about 5 3/16 inches long capped. They came in black, brown web and marble paneled, golden brown stripe, green stripe, silver web, green brick, and olive marbled striped patterns. Several elaborate gold plated cap bands were used, including repeating arrows, a repeating angled T pattern, and a repeating teardrop with triangle cutout.