Improved Strat tuning stability, sustain and reliability! The baseplate holes are elongated so the screws won't bind, for smooth, accurate pitch return. For tuning stability, the string mounting holes are staggered in the steel block for more consistent string angle over the adjustable locking bent-steel saddles.54 mm (2-1/8") string spacing.Included with the set are: springs, spring claw, arm with white plastic knob, mounting screws, saddle adjustment screws and allen wrenches.