Work like a BOSS Europe's No. 1 highlighter: Since its introduction in 1971, the STABILO BOSS ORIGINAL has been a popular choice for school children, office workers and design professionals. Product features: It can be left with its cap off for up to 4 hours without drying or running out. Had a hectic day? No need to worry if you forgot to put the cap back on. The STABILO BOSS ORIGINAL can be easily refilled following periods of intensive use.