Graph Tech, Made in CanadaRatio – Tuned Locking Machine Heads are the first and only machine head to incorporate the different string gauges into the tuning equation. We balanced the individual gear ratios to each string dramatically simplified the tuning process. No more overshooting the G string or twisting away on the high E string. With Ratio, each half key turn equals one semitone change on all strings! Quicker, more accurate tuning on every string.The PRL-8731’s are a set of Locking Ratio Tuned Machine Heads for an electric guitar that uses six inline tuners. It has a classic shaped button, has a two pin casing and the InvisoMatch Mounting Plates (sold separately) make for easy installation on most headstocks.Features:Ratio Tuning6 inline2 Pin CasingLockingColor: ChromeWashers, Busings & Install instructionsInvisoMatch Plates are sold separatelyItem Number: PRL-8731-C0