Gunjac or Bajs is a viloncelo like instrument, but with only two strings. The players of gunjci are called Bajsisti.
Legendary Gunjac builder and player - Ottavio Štokavac (1921-2006), from the village of Kolari, near Buje.
"Bajsi u Draguću", 2005: Ottavio Štokavac (violin) and Marko Tončić (gunjac)
in a beautiful glagolitic town of Draguć, Istria, Croatia
Source: Puna je Istra bajsista, 16th Festival "Bajsi u Draguću", 2005
Women are also playing gunjac! A family orchestra Fameja from Roč,
playing on 16th Festival "Bajsi u Draguću", 2005 (the same source)