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3+3 RATIO Lefty Electric Locking Machine Head Vintage Button (PRL-8341-L, Select Finish)

3+3 RATIO Lefty Electric Locking Machine Head Vintage Button (PRL-8341-L, Select Finish)



Regular price $160.94 USD
Regular price Sale price $160.94 USD
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Select Finish
Select Button Style

RATIO® patented gear technology
RATIO® - Calibrated Machine Heads incorporate different string gauges into the tuning equation.

From Low E to High E 39:1, 24:1, 20:1, 35:1, 20:1, 12:1.

We 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 adjustment. Predictable, precise tuning, on every string.

RATIO Machine Heads explanation video


The PRL-8341 is a left-handed set of Locking RATIO® Calibrated Machine Heads for electric guitar that use 3 x 3 tuners, such as Gibson style and PRS style guitars.

A great upgrade over a single gear machine heads, such as Grover, Schaller, Sperzel, Kluson, etc.

Probably the easiest machine heads to retrofit using the Invisomatch Mounting Plates which allows you to use your existing screw holes.


It has a two pin casing that can be used as is, or with our Patented InvisoMatch Mounting Plates [opens in new tab].

4 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.


3x3 tuners set  Ratio Tuned Machine Heads: The New Standard In Tuning Technology


Gear ratio: unique for each string position - one turn-one tone
Peg holes diameter required: 13/32" (10mm)
String post diameter: 0.236" (6mm)
String post length to string hole: 0.910” (23mm)
Weight per single machine head: 0.083lbs (38g)
Weight per set of six: 0.496lbs (225g)
String diameter up to 72 gauge
Includes 6 machine heads, mounting screws and bushings
Includes complimentary 4 sets of aluminum mounting plates

Staggered Ratio Measurements.pdfRatio Installation Guide.pdfRatio Installation Guide Video

Reviewed in the United States on November 25, 2021

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Rated 5.0 stars
Based on 2 reviews
Total 5 star reviews: 2 Total 4 star reviews: 0 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
100%would recommend this product
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2 reviews
  • RM
    Rex M.
    Verified Buyer
    I recommend this product
    Rated 5 stars
    1 month ago
    Ratio machine heads

    Excellent, easier tuning for sure

  • SH Profile picture for Steve logo
    Steve H.
    Verified Buyer
    I recommend this product
    Rated 5 stars
    2 months ago
    Best locking tuners I’ve ever used!

    The best locking timers I’ve ever used!

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