The Microlab CM-81N is a 3x3 hybrid coupler with N female connectors. The coupler connects 3 inputs to 3 outputs with minimal interaction and PIM (intermodulation).
Hybrid couplers are used to combine wireless carriers in the band to a single antenna feed or distribution cable. In DAS applications, all three outputs may be used to feed different cables, essentially providing lossless combining. Any unused ports must be terminated in 50Ω and results in a 4.8 dB loss in each signal.
This is a low PIM coupler <-150 dBc (2 x +43 dBm tones). It has N-female connectors.