This set includes paper and cardboard punchings for balance rail and front rail.  The balance rail punchings are used for leveling the keys and the front rail punchings are for adjusting the amount of key dip on each key so that it is at the correct level and is consistent from one key to the next.

Set includes:

• 100 of each of 9 different sizes of piano balance rail paper and cardboard punchings ranging from size .003" to .045" Piano Keyboard Paper & Cardboard Punching Set