Gotoh 510TS-SF2 Series Vintage Style Tremolo Bridge Chrome Gotoh 510TS Series Tremolos are machined with Chrome Molybdeumn Steel knife edges to withstand years of abuse and trouble free use Comes stock with a vintage steel block with more mass and better tone These are top of the line Gotoh tremolo units Tremolo-unit includes the following accessories: Arm, Spring, Spring-holder, Wrench, Stud-bolt, Screw etc Hardware included.