So far, only the 20-note version of Muro Box is available for sales. If you wish to buy Muro Box when we have an advanced version “Muro Box N40” (whose music range will be A3-C7, including flats and sharps), please sign up for our email for Muro Box N40 via this form. We will send you a monthly update to report our product development status and collect your feedback for our design.    Our design concept is to present the beauty of mechanical movement as the key attraction of music box. Welcome to watch this video to better understand our current design.