The Riester duplex® is a high quality stethoscope with double chest-piece. The improved acoustic is made for better productivity. It comes with double-headed chest-piece which is of two types one in chromium-plated brass and another one in specially lightweight aluminum, galvanized. It has special membrane for perfect auscultation with Ø 48 mm and flat and soft non-chill rims for better adaptation on the skin. The bell is of Ø 36 mm with 77 cm length. A pair of replacement ear-tips and a replacement membrane come with duplex®.