Graph Tech 4 String 4-In-Line Bass Ratio Open Back Classic Clover Leaf Button - Chrome (PRB-4401-C0)

RATIO patented gear technologyRATIO - 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. The PRB-4401 is a right-handed set of RATIO Calibrated Machine Heads for BASS that use 4-in-line configuration. Every string reacts the same to any tuning adjustment. Predictable, precise tuning, on every string. In order to achieve the higher gear ratio's, Ratio's are the world's first machine heads using a double envelope gear design with a hardened steel gear. Amazingly smooth and super strong.