ORIGINAL BOX. 900 series were Radio Pens introduced in 1931. R. ESTERBROOK & CO.'S RADIO PENS No. 939 dip pen nibs. Sealed, unopened, protective wax paper shipping wrapper still intact. Made in Camden, N.J. New York marked on front of box. Approx. 2 1/4 x 1 1/2 x 1. Listed in the Esterbrook Pen 1938 Catalog. All there for you to see, please enlarge all images as part of my description. Thanks for looking appreciate it!