H510-44M D'Addario Helicore cello string set 4/4 H511-44M D'Addario Helicore cello string A-1 4/4 H512-44M D'Addario Helicore cello string D-2 4/4 H513-44M D'Addario Helicore cello string G-3 4/4 H514-44M D'Addario Helicore cello string C-4 4/4 H512-44L D'Addario Helicore cello string D-2 4/4 H513-44H D'Addario Helicore cello string G-3 4/4 H514-44H D'Addario Helicore cello string C-4 4/4 H512-18M D'Addario Helicore cello string D-2 1/8