The main difference between an ultra-fine gastroscope and an ordinary gastroscope is the difference in outer diameter. The outside diameter of a normal gastroscope is about 9mm-10mm, while the outside diameter of an ultra-fine gastroscope is about 5.5mm. An ultra-fine gastroscope can enter the stomach through the nose, also known as a nasogastroscope. It is thinner and can enter the narrow digestive tract. Patients with esophageal strictures, duodenal strictures, etc., when stents are to be placed or operations to be observed, can be observed through the ultra-fine gastroscope. Because the mirror is thinner, the orifice for biopsy is also thinner, and there are matching instruments for biopsy with ultra-fine gastroscopy, and the biopsy specimen is usually smaller.