Skinny can line and letter writing nib. Writing stable for low center of gravity design. 4 mm easy to rely on the ruler guide pipe. Knurled prevents hand slippage. A window display you can use core hardness.
?? core diameter: 0. 5 mm ?? internal core: HB
Axis: play ABS to gold, grip: brass clip: iron?@
Erase replace ?FZ2-1 N?@