Turbo is a “rounded” sans-serif from the constructive grotesque font style. Special attention has been given to the stem-endings. They are not mechanical semi-circles. Rather, in all the various positions, they are manually shaped so that their curves work, and make sense from a design perspective. Thanks to tiny factors like this, they form a closed base line.
Turbo Fonts are available in different versions:
OpenType Basic covers the Western and Central European character set and contains one set of numerals (tabular). OpenType Expert covers the Western and Central European character set and contains various numerals and other OpenType-Features for advanced typographic performance.
OpenType Basic contains only the black characters, OpenType Expert contains the grey characters too.