A：Clinically, according to whether the endoscope body can change direction, it can be classified into two types: hard mirror and elastic soft mirror. The hard mirror (RIGID ENDOSCOPE) is a prism optical system. The biggest advantage is that the image is clear, and it can be equipped with multiple working channels to select multiple viewing angles. FLEXIBLE ENDOSCOPE is an optical fiber optics system. The most important feature of this fiber optic endoscope is that the lens part can be manipulated to change direction and expand the application range, but the imaging effect is not as good as that of the hard mirror.