F900 is a load class of EN124 and ГОСТ 3634 (СТУ) standards. It is applied to manhole covers in areas imposing particularly high wheel loads, i.e. aerodromes.

Manhole Cover with Coat of Arms of the Czech Republic
Czech Republic, Prague
Manhole Cover with Prague Coat of Arms
Czech Republic, Prague
Pražska Kanalizace
Czech Republic, Prague
Berliner Wasserbetriebe Manhole Cover with Berlin Landmarks
Germany, Berlin
Hydrotec Manhole Cover SN D400 EN124-2
Germany, Nuremberg
Manhole Cover with Dresden Coat of Arms
Germany, Dresden
Manhole Cover with Trier Coat of Arms
Germany, Trier
Munich Coat of Arms Manhole Cover
Germany, Munich