More information· Stable up to 70 ° C · Developed especially for summer, but also for high temperature workplaces · This solves a common problem of standard mines, which are more sensitive to higher temperatures and can soften around 30- 40 ° C. · For most surfaces except smooth / shiny · Pre-sharpened points · Sturdy case · Cases of 8 assorted leads: 3 graphite, 3 red, 2 white