Dienstglas button flap or Knopflasche and strap set marked bek 1941

Textbook set of a matching Dienstglas button flap and neck strap in very good condition.  Both parts are nicely marked bek 1941 which indicates production by Hensoldt-Werk fuer Optik und Mechanik, Herborn, this is for me the first time to encounter this manufacturer on accessories! Finding marked spare accessories is hard, let alone a matching set of them. Hard to upgrade set!