MT-RJ Connector is becoming more popular in datacom applications which use duplex transceivers. It uses almost the same real estate in the patch panel and networking equipment as other 2.5mm ferrule connectors but doubles the port capacity.
MT-RJ Connector is so difficult to test, as most test sets do not allow direct adaptation to the connector. If you have to use hybrid(ST or SC to MT-RJ)reference cables, you cannot di a Method B(one jumper reference) insertion loss test. Usually the solution is to do a third cable(Method C) reference.

Part#                             Product   Description

KSUN 010006-20-SM-PC          Connector MTRJ    2.0mm  SM 

KSUN 010006-20-SM-PC          Connector MTRJ    2.0mm  SM (with pin)

KSUN 010006-20-MM-PC         Connector MTRJ    2.0mm  MM 

KSUN 010006-20-MM-PC         Connector MTRJ    2.0mm  MM (with pin)