A Schild – AS Calibre 1920 – Part No. 771 Mainspring with brake spring (NOS) Related posts: A Schild – AS Calibre 1902 – Part No. 775 Brake spring (NOS) A Schild – AS Calibre 1906 – Part No. 775 Brake spring (NOS) A Schild – AS Calibre 1920 – Part No. 775 Brake spring (NOS)