This is the string I use it comes in pairs. It's 100 percent cotton and does not slap or buzz inside the bars like plastic string ("parachute cord"). It is enough for one instrument. One order includes two strings (enough for one instrument). The ends are treated and stiff for easy threading. It is the perfect diameter for the string holes. Did you know that the diameter of your string greatly effects the pedal damping? View this video to see how/why...  https://youtu.be/Zrb4u8ytD3w?list=PL_dn1PlcwxoK86clyawxuMLLu4L7uRqyf