Grover 210N Pedal Steel Guitar Machines, machine heads for pedal steel guitar, shortened string post and bushing are designed for the slotted head of a pedal steel, closed gear, 10 pieces: 5x left, 5x right, Accommodates a headstock thickness varying from 7.1 mm (.256”) to 10.16 mm (.400”), axis diameter without mounting sleeve: 6 mm, mounting sleeve diameter: 9.91 mm, nickel finish