This is a Parker Sac Duofold Lady button filler in Green, the same filling system as the original Duofold. The Green color includes green, gold and black elements. Sac Duofold models were also available in striped Blue, striped Maroon, and Black. This 5 1/8 inch long pen is date coded 1942. Parker did not mark button fill pens with the Blue Diamond Guarantee and also gave them plainer unhallmarked gold nibs. The catalog says the Duofold nibs are 14 karat gold. They sold for $2.95 and the matching pencil was $2.00. It's hard to see from the plating loss, but the cap band is plain.