Royal Classics SRR70 Serranito Nylon Guitar Strings, Medium-High Tension Royal Classics Serranito set features high tension silverplated basses, RC Cristal 1st and 2nd strings and a RC UltraSon 3rd string. Developed for and used by flamenco guitar legend Victor "Serranito" Monge. Treble gauges: .73mm/.029", .83mm/.033", .90mm/.035" Bass gauges: .78mm/.031", .86mm/.034", 1.09mm/.043" Treated with an ultra thin proprietary anti-oxidant coating. Crafted in Spain