GraphTech RATIO Electric Guitar Locking 4+3 Mini Contemporary Machine Heads ~ Chrome

The PRL-8521 is a right-handed set of Locking RATIO® Calibrated Machine Heads for electric guitars that uses a 4 x 3 tuner configuration.

Fits many Gibson/Epiphone, PRS-style guitars, and any other guitar with a 4+3 headstock.

It has a two-pin casing that can be used as is, or with our Patented InvisoMatch Mounting Plates.

4 different sets of InvisoMatch mounting plates in brushed aluminium are included to make installation on most guitars fast and accurate by using your existing screw mounting holes.

Gear ratio: unique for each string position - one turn-one tone
Peg holes diameter required: 10mm (13/32")
String post diameter: 6mm (0.236")
String post length to string hole: 23mm (0.910”)
Weight per single machine head: 38g (0.083lbs)
Weight per set: 266g (0.581lbs)
String diameter up to 72 gauge
Includes 7 machine heads, mounting screws, and bushings
Includes complimentary 4 sets of aluminium mounting plates

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

From Low B to High E 48:1, 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.