Replacement string for French horn rotary valves. It is about 0.1mm thinner than Yamaha's string. The feel when pressing changes, improving lever action. Perfect as a stylish accent for your instrument or as a gift for your horn section friends. * The color of the backing card is random. It's a surprise when it arrives. * Can also be used as a replacement string for string-type trombone rotary valves. * The string is durable, but it is not a string that will not break like diamond cord. [Model Number] SMK-HRSTBK [Color] Black [Length] 1m [String Thickness] 0.8mm Shipping will be via regular mail to keep shipping costs down. Search "SMKC Horn String Knotting" for instructions on how to tie the string. If it's difficult to replace, ask a music store to do it for you.