For standard guitars, set of 6. A triumph in engineering and styling. Available in Nickel, Chrome or Gol keystone buttonsd, their housing provides a maximum bearing for worm, gear and string post, with a gear ratio of 14:1 for superbly accurate tuning, and no string slippage. The gear box also has a special lubricant for a lifetime of trouble-free service! They also include 5/8? washers, bushings and wood screws.