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Graph Tech Graph Tech

Graph Tech Ratio 6-In-Line Lefty Electric Locking Tuning Machine Heads Black 6 String

Q&A SKU #M02019000001001
136.8 $136.80
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This item is backordered but is available to reserve now. You will not be charged until the item ships.

Style: Black 6 String

Black 6 String $136.80 Chrome 6 String $136.80
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Locking Ratio calibrated machine heads for electric guitars that use 6-in-line tuners.

The Graph Tech Ratio 6-in-line lefty electric guitar locking machine heads incorporate different string gauges into the tuning equation. Graph Tech balanced the gear ratios to each string, simplifying the tuning process. With Ratio, a half turn is a semi-tone. Every string reacts the same to any tuning adjustments, delivering predictable, precise tuning on every string. The Graph Tech PRL-8721-L is a left-handed set of locking Ratio calibrated machine heads for electric guitars that use 6-in-line tuners.

It has a two-pin casing that can be used as is, or with Graph Tech’s InvisoMatch mounting plates. Four different sets of InvisoMatch mounting plates in brushed aluminum are included to make installation on most guitars fast and accurate by using your existing screw mounting holes.


  • Includes:
  • Includes 6 machine heads, mounting screws and bushings
  • 4 complimentary sets of aluminum mounting plates included

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Ratio 6-In-Line Lefty Electric Locking Tuning Machine Heads Specifications:

  • Gear ratio: 39:1, 24:1, 20:1, 35:1, 20:1, 12:1
  • Peg holes diameter required: 13/32" (10mm)
  • String post diameter: 0.236" (6mm)
  • String post length to string hole: 0.910” (23mm)
  • String diameter up to 72 gauge

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