These compact guitar machines are a triumph in engineering and styling. The housing provides for maximum bearing for worm, gear, and string post. Gear ratio is 14:1 Worm and gear are precision-cut for perfect mesh, eliminating backlash and slippage. Countersunk tension screw permits players to regulate tuning tension to any degree. Rotomatic gear boxes have lifetime lubricant for trouble-free service. Includes 5/8" washers, bushings and wood screws.