07 NOMOS Club Sport neomatik 42 date black crown
Photographer: NOMOS Glashütte
To prevent water from reaching the mechanical caliber during diving, sports watches are fitted with plastic or rubber seals in the case back, glass and crown. Watchmakers must pay particular attention to the crown, as it is connected to the movement via the winding stem. Waterproof sports watches, such as Club Sport neomatik 42 date black shown here, are therefore usually equipped with a screw-in crown. The red marking on the crown stem indicates that it has not yet been screwed in.