Type A (straight-through type): The cores at both ends of the jumper are arranged in the same position, that is, 1 at one end corresponds to 1 at the other end, and 12 at one end corresponds to 12 at the other end. The orientation of the keys on both ends is opposite, and key up corresponds to key down.

　　Type B (interleaved): The positions of the cores at both ends of the jumper are opposite, that is, 1 at one end corresponds to 12 at the other end, and 12 at one end corresponds to 1 at the other end. The key orientations at both ends are the same, that is, key up corresponds to key up, and key down corresponds to key down.

　　Type C (interleaved pair): Type C MPO jumper is a pair of adjacent cores crossed, that is, the core 1 at one end corresponds to 2 at the other end, and the core 12 at one end is 11 at the other end. The key keys at both ends are also in the opposite direction, and key up corresponds to key down.

　　The three polarities of connection methods and the different polar methods use different types of MPO trunk cables. However, all methods utilize duplex patch cords to form fiber optic links. The TIA standard also defines two different types of LC or SC duplex fiber optic patch cords to complete end-to-end duplex connections: Type A-A (crossover) patch cords and Type A-B (straight-through) patch cords.

　　Compared with other optical fiber connectors, MPO connectors have the characteristics of small size, high precision and high density. Its appearance has greatly improved the popularity of optical networks and reduced production costs. Therefore, MPO jumpers are widely used in environments that require high-density integrated optical fiber lines in the wiring process, such as FTTX, 40/100GSFP, SFP+ and other transceiver modules or connection applications inside and outside the device.