Common for heavy-duty industrial equipment and outdoor security cameras. Completely dust-tight and resistant to heavy rain or water jets.
To get the clean, "best" version, purchase it directly from the IEC or iec 60529 pdf best
This indicates the level of protection against harmful ingress of water. iec 60529 pdf best
Protected against water jets projected by a nozzle (6.3 mm) from any direction. iec 60529 pdf best