The FSB European Mortise Lock (EML) is a DIN 18251-1 Class 3 mortise lock manufactured in Germany. It is field reversible and available to accept a European style profile cylinder. This is a high end residential favorite in the US as it will fit an 1 3/8" thick door.

Specifications
DIN Grade 3 Mortise Lock field reversible
PZ = 2 13/16" (72 mm) CTC
WC = 3 1/16" (78 mm) CTC