Pentel Ain STEIN leads are a new generation of darker, stronger graphite refills from the global leader in mechanical pencils. Believe it or not, the name is an acronym: STEIN stands for “Strongest Technology by Enhanced SiO₂ Integrated Network.” SiO₂ is silica, typically found in nature as crystalline quartz. Pentel’s engineers have used SiO₂ to create a microscopic skeleton that keeps Ain STEIN leads from breaking.

In addition to their unusually strong construction, Ain STEIN leads offer darker marks and smoother writing than previous pencil lead technology. Despite their dense graphite load, they’re also smudge-resistant.

Pentel Ain STEIN leads come in a unique, compact case, thinner than your pencil and featuring a twist top that dispenses a few leads at a time. The translucent window in the front of the package allows you to see how many leads are left inside.

40 leads per package. 60 mm length. Made in Japan.