Musiclily Pro 4.8mm Tremolo Arm Screw-in Inch Size for USA Strat Electric Guitar Installed only once after purchase. Almost unused. Opened. For USA Fender, Classic Vibe Strat style electric guitars with tremolo bridge systems. Made of high-quality steel with a plastic cap, durable and rust-resistant, perfect for guitar replacement and upgrades. Inch size #10-32, screw diameter: 4.8mm The size fits perfectly with the company's MIM style tremolo block 10.5mm string pitch type.