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| Regional areas: | 3-4 business days |
| Remote areas: | 3-5 business days |
RATIO® patented gear technology
RATIO® - Calibrated Machine Heads incorporate different string gauges into the tuning equation.
From Low E to G - 48:1, 36:1, 25:1, and 23:1.
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.

The PRB-4401 is a right-handed set of RATIO® Calibrated Machine Heads for BASS that use a 4-in-line configuration.
In order to achieve higher gear ratios, Ratio are the world's first machine heads using a double envelope gear design with a hardened steel gear. Amazingly smooth and super strong.
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