The Rollerball Refills 338 from Pelikan have a solid tip of stainless steel and a tungsten carbide ball.
Compatible with most rollerball pens using an International standard rollerball refill.
Available in Colour: black, blue,
F = fine (0.8 mm Ø)
M = medium (1 mm Ø)
B = broad (1.2 mm Ø)