Super Sensitive Red Label 6147 Cello C String, 4/4 Red Label strings are full core, nickel-wound strings that provide excellent tonal quality and dependability at an affordable price Since 1930, Super-Sensitive "Red Label" strings have been the choice of students and professionals alike Designed with the student in mind, Red Label strings are favored and recommended by Suzuki Method instructors, school and private music teachers, students and professionals Since 1930, Super-Sensitive "Red Label" strings have been the choice of students and professionals alike Designed with the student in mind, Red Label strings are favored and recommended by Suzuki Method instructors, school and private music teachers, students and professionals