Looks like some type of magnet wire cables to me. I had a pair of the original Anticables speaker wire that looked similar to that, but had a different color of enamel on the outside.
If it is super stiff, solid core, with thin enamel coating, it's probably magnet wire. Also, considering the type of banana plugs on them, they are probably a DIY build.
If it is super stiff, solid core, with thin enamel coating, it's probably magnet wire. Also, considering the type of banana plugs on them, they are probably a DIY build.