Boston double action truss rod, 6x9mm bar model, 4mm allen nut, 360mm length, for acoustic guitar
Boston double action truss rod, 6x9mm bar model, 4mm allen nut, 420mm length, for classic guitar
Boston double action truss rod, 6x9mm bar model, 4mm allen nut, 460mm length, for electric/acoustic guitar
Boston double action truss rod, 6x9mm bar model, 4mm allen nut, 590mm length, for bass guitar
Boston double action truss rod, 6x9mm bar model, 4mm allen nut, 610mm length, for bass guitar