The SL-4x4 from Sercalo Microtechnology is a Fiber Optic Switch with Insertion Loss 2.5 - 3.5, 1.5 - 2.5, 1.2 - 2.0 dB, Operating Temperature 0 to 70 Degree C, Optical Power 150 mW, Polarization Dependent Loss 0.10 - 0.18 dB, Storage Temperature -40 to 70 Degree C. More details for SL-4x4 can be seen below.