This is an almost professional derivative stethoscope bell. With the appropriate "Litmann" membrane, that you can buy online, the quality of the sounds during auscultation is not disappointing at all. For doctors that lost their LitmannPrint the two parts (base and handle) and three pins. Insert the pins in the respective holes of the base, put glue and assemble. A clamp to keep the pieces in the correct position is reccomended