F1F series. Direct Drive,Flat-bed Interlock Stitch Machine

F1F-U356/NN . Direct Drive, Flat-bed  Interlock Stitch Sewing Machine.

F1F-U356/SN . Direct Drive, Flat-bed  Interlock Stitch Sewing Machine, Auto Thread Trimmer.

https://www.youtube.com/watch?v=RrKbEh45lCE