GOTOH H.A.P.-M. Combining the ability of Post Height Adjustable and Magnum Lock. Keeping the current function, locking stability has been improved with the introduction of new smaller string holes on 1st, 2nd and 3rd string posts. Locking feature gives a machine head that is the perfect choice for flat peg-head guitars equipped with Vibrato. Height adjustable posts take away the guesswork by allowing you to dial in the exact angle you need for, friction, string pressure/tension and open string sound and sustain. Ideal for flat style peg heads when string trees need to be eliminated.