The Lisle Stethoscope with Magnetic Holder, No. 52520, is designed to quickly pinpoint the source of noises in engines, transmissions, differentials, and bearings. The Stethoscope includes a magnetic accessory that can be attached to the end of the stethoscope probe, allowing it to be held in place handsfree so the technician can check for chassis noise without another technician. It features an unique sound chamber and a thin diaphragm to amplify sound.