This is the handiest music transposing device ever sold. It was invented and copyrighted by us. Music students, composers and teachers can transpose any music instantly by a single turn of a wheel! Transposes notes, chords and key signature in ONE STEP! Pop the Transposer off the back card and turn the it clockwise to transpose higher and counterclockwise to transpose lower. Transposes notes, chords and key signature in one step. Transpose scores quickly without error. Transposing instructions included. Learn key signatures and the notes of all major and minor scales. The Transposer is 5″ in Diameter and made in the USA. Note: This item is shipped with the back card folded over the wheel. This is to protect the wheel in transit. The back 8×11 card is packaging only. You gently pull the card off the wheel before using it.