The stethoscope is the most important diagnostic tool ever developed. Using it correctly will be your most important challenge. We here at Stethoscope.com strive to provide useful education materials that will supplement your training. The software driven study guides will help you hone your skills at auscultation. The books, charts and models will help with your continued study of human anatomy and conditions. Each product includes a 30 day money back guarantee. You can also place your order via the telephone at (800) 238-2448.