A Schild – AS Calibre 1913 – Part No. 301 Regulator for flat hairspring (NOS) Related posts: A Schild – AS Calibre 1704 – Part No. 301 Regulator for flat hairspring (NOS) A Schild – AS Calibre 1711 – Part No. 301 Regulator for flat hairspring (NOS) A Schild – AS Calibre 1916 – Part No. 301 Regulator for flat hairspring (NOS)