CL3 Rotosound Grade 1 Professional string set classic 573 Pro rectified nylon trebles & silverplated basses CL4 Rotosound Grade 1 Professional string set classic Black n' Silver rectified black nylon trebles & silverplated basses NRH1 Rotosound Grade 1 Professional E-1 string for classic guitar NRH2 Rotosound Grade 1 Professional B-2 string for classic guitar NRH3 Rotosound Grade 1 Professional G-3 string for classic guitar NRH4 Rotosound Grade 1 Professional D-4 string for classic guitar NRH5 Rotosound Grade 1 Professional A-5 string for classic guitar NRH6 Rotosound Grade 1 Professional E-6 string for classic guitar