String Fuel is a hybrid blend of refined naturally occurring oils speed blended with premium quality mineral oils to deliver a string cleaner and lubricant unlike any other. Your strings will last longer and sound better while reducing finger noise and enhancing your speed. Silicone free and safe for any finish and even conditions unfinished fretboard wood. Includes the String Fuel solution impregnated in a no-mess ergonomic applicator and a lint free microfiber cloth that stores inside the applicator handle.