Function --- It can help prevent string breakage, improving tone and sustain and keeping your guitar in tone. High strength material --- Zinc alloy block and brass screw, are anti-rust and stable, durable to use. Adjustable --- Total 6pcs/set in a package, including three kinds of height and each kind 2pcs, to meet your installation needs. Convenient to install --- Easy to install onto guitar bridge. Wonderful replacement --- Nice replacement for electric guitar.