MTRJ

MTRJ (Mechanical Transfer-Registered Jack) is a standard type of fiber optical connector termination. It's a duplex fiber-optic cable connector with both fibers in a single polymer ferrule.

MTRJ closely resembles an RJ-style modular plug, even getting part of its name from the resemblance. MTRJ connectors are always duplex in that they hold two fibers. The body and ferrule are normally made from plastic or plastic composite, and lock into place with a tab (just like a modular RJ-style plug).

MTRJ connector uses pins for alignment and has male and female versions. Multimode only, MTRJ connector is field terminated only by prepolished/splice method.

Based on a specification by NTT (the Japanese telecommunications company), MTRJ it was developed by AMP/Tyco and Corning and is a popular small-form-factor fiber-optic connector.