Grover 409FN Mandolin Machines
                                
                                
                             
                            
                         
                            
                            
                        Grover 409FN Mandolin Machines, Set of Machine Heads for Mandolin, Tuning pegs of different lengths for standard ""F""-style mandolins, Configuration: 4 left / 4 right, 4-On-A-Plate design, Mounting diameter with mounting sleeve: 8.30 mm, Shaft distance: 23 mm, Open, Worm thread above gear, Gear ratio 18:1, Round pearloid buttons, Finish: Nickel plated