The rounded frame shape of these glasses is recreated from earlier models of the legendary Danish Sirius Patrol. These were needed to protect the wearer in extreme weather conditions from light reflected from the snow. In this modern variant, the lenses can be changed by means of a simple snap system. The inner lens frame can also be optionally exchanged for a form with reinforced side protection. Lenses with a single focal value or multifocal lenses as well as models without vision correction can be inserted. A hard-shell case is supplied for each frame as well as a soft pocket for a cleaning cloth and two pairs of replacement lenses.