Augustine produces 4 different series of classical guitar strings;The best known Classic sets (black, gold, red and blue) have identical nylon trebles in normal tension, the sets differ in the different tensions of the wound bass strings (black = low, gold = medium, red = medium, blue = high). This logic is continued in all subsequent series.;All strings marked GOLD have a gold-coloured winding of brass-plated copper bass strings in medium-low tension;Classic Blue Label normal/high tension;Standard treble strings in normal tension;Silver-plated bass strings in high tension;Diameter and tension:;E1 normal: .028"/0.71mm, 7.81kg/17.21lbs;H/B2 normal: .032"/0,81mm, 5,84kg/12.88lbs;G3 normal: .040"/1.01mm, 5.56kg/12.25lbs;D4 high: .0305"/0.77mm, 7.44kg/16.41lbs;A5 high: .036"/0.91mm, 7.149kg/16.75lbs;E6 high: .045"/1.14mm, 7.21kg/15.89lbs;