Roller Refill by Caran d’Ache. This is a metal cartridge refill for Caran d’Ache rollerball pens including Hexagonal, Ecridor, Madison, etc. Available in a fine line width in either blue or black. Please note that the image is only a rough guide (the thinner front end of the refill is black plastic in reality, not metal).
Size: 110mm x 6mm.
Blue: 7610186 805196 (single) / 7610186 580277 (pack of 5)
Black: 7610186 805219 (single) / 7610186 580284 (pack of 5)