Nib: No. 1551 Fine Student
Esterbrook produced a series of LJ sized pens now commonly called "Icicles" due to the pin striping of the plastic.
Esterbrook LJ "The classic Double Jewel" BrownLever-filled
The "J" pen, introduced in 1948, is the classic postwar Esterbrook.
The classic double jewel J. These came in three sizes J (full sized), LJ (slender), and SJ (demi) and in the classic six colors.
The earliest double jewel models simply have the "Esterbrook" imprint, whereas most with the Registered symbol (®). J's have double round black jewels with the name on the clip.