The Hipshot™ Tremsetter system adds even greater stability to Stratocaster® tremolo bridges. Mechanism replaces center tremolo spring, eliminating "flutter" and increasing tuning stability. Compatible with most vintage-style and modern tremolo-equipped Stratocaster guitars (some modification may be necessary for proper installation). Mounting hardware and installation instructions included.Brand New. Genuine Fender 0990811000. UPC 717669448189.