The Guitar Musicaid Sliderule is a handheld instructional tool that helps guitar players learn notes, scales, chords, and finger placement. It contains a guitar fingerboard card and sliding window that reveals this information. Moving the slider shows fret positions, scales, chords, and the relationships between notes. It is priced at $15.99 and benefits both students and teachers by providing an engaging way for guitar players of all ages to learn the fundamentals of the instrument.