"Grover 409FVN Mandolin Machines, Set of Machine Heads for Mandolin, Tuning pianos of different lengths for vintage ""F""-style mandolins, Configuration: 4 left, 4 right, 4-On-A-Plate design, Mounting diameter with mounting sleeve: 8.30 mm,..."Grover 409FVN Mandolin Machines, Set of Machine Heads for Mandolin, Tuning pianos of different lengths for vintage ""F""-style mandolins, Configuration: 4 left, 4 right, 4-On-A-Plate design, Mounting diameter with mounting sleeve: 8.30 mm, Distance...altro...