They call it "Open Book"

The graphite core itself is more densely packed than a standard pencil's

100% cotton

Extra tips that are suitable for MTN Water Based Marker Ultra Fine 0

lower-friction polymer than a typical rubber eraser

scrikss graph x mechanical pencil 0 5 mm grey Boner They call it "Open Book"The Scrikss Graph X 0. 5 mm in satin grey is a brass mechanical pencil built for fine, technical linework hair thin keylines, cross hatching, and detail work where precision matters more than speed. The hexagonal body keeps it from rolling off a slanted drafting table, and the lower section has diamond cut knurled ridges for a secure grip. Weight is centered low toward the tip, which keeps your hand relaxed rather than tiring out over long drafting