Chordophone called Zlobcoki is an old,  folk instrument. Zlobcoki belong to a group of instruments called chordophones. Chordophones are one of the oldest musical instruments. Chordophone are divided into  pulled chordophones, hammerhead chordophones and string chordophones. Instruments in which the sound source is one or more strings tensioned between two specified points.

Zlobcoki is an instrument with a very resonant sound, used in Carpathian Area (Podhale) before the spread of the violin; currently resumed in the folklore movement. Zlobcoki are hand made from wood and metal.
The films describes the history of described instruments - Zlobcoki, and gives the opportunity to listen to their sound in traditional folk music from the region of its origin – Carpathian Area (Podhale) in Poland.

https://www.youtube.com/watch?v=2Ij-xOMAdgk