High-quality strings since 1956; Steel core, metal alloy or fibre winding; Warm, brilliant sound and durability; The “Classic” series standard strings; The A+D strings of the “Special” series are 0.01 mm thicker; The “Superior” strings are 0.02 mm thicker than “Special”; The “Silver Sound” G strings with flexible steel core and silver winding; A “Superior” ; String strengths/tension: ;dolce 0.77mm/17.7kp/38.9lbs; medium 0.78mm/18.5kp/40.7lbs; forte 0.79mm/19.1kp/42.0lbs;