Fiber optic adapters, also known as flanges, are mainly used for connecting and fixing fiber optic connectors, allowing optical signals to be transmitted with minimal insertion loss. The connection method of MPO fiber optic adapters is different from that of single core SC fiber optic adapters. SC fiber optic adapters are equipped with ceramic sleeves inside, which are used for precise alignment when connecting SC connector cores. MPO adapters use two guide holes with a diameter of 0.7mm on the left and right sides of the MPO connector core end face and guide pins (also known as PIN pins) for precise connection. Therefore, MPO adapters are not classified as single or multi-mode. SC fiber optic adapters are classified as single or multi-mode because the quality of the sleeves is different. MPO adapters are widely used in communication system base stations, optical distribution frames (ODFs) in building data centers, MPO boxes, and various testing instruments.