Graphtech Ratio 3+3 Electric Locking Machine Heads Vintage Black PRL-8341-B0 

A right handed set of Locking Ratio Tuned Machine Heads for electric guitar that use 3 per side tuners. Fits many Gibson, Epiphone style guitars and a lot of acoustic guitars if you want to upgrade to a locking set of machine heads. 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 aluminum are included to make installation on most guitars fast and accurate by using your existing screw mounting holes. You can upgrade to the matching finish InvisoMatch Plates 

Ratio - Tuned 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.