Famous for first-class strings since 1956;Steel core string wound with thin filaments of pure or alloyed metal;Warm, brilliant tone and long life;"Classic" Series - standard strings;"Special" Series has 0.01 mm thicker A+D strings;"Superior" Series is 0.02 mm thicker than "Special";"Silver Sound" Series has G and C strings made of a highly flexible steel core with a top coil of pure silver;A "Classic" Chrome Steel ;String gauges/tension:;dolce 0.74mm/16.3kp/35.8lbs;medium 0.75mm/17.9kp/39.4lbs;forte 0.76mm/18.5kp/40.7lbs;