D'Addario black nylon strings, medium scale, .050 .065 .085 .105. Used for about a month on a Hefner Ignition bass. Picked. Although not Hofner-specific strings, they fit into the peg holes somehow. I don't know if they will fit other manufacturers' violin basses. They have a long lifespan and a warm tone like flatwound strings. Due to the nature of the product, returns are not accepted.