The V3100-S from OEQuest is a Fiber Optic Attenuator with Attenuation 1 dB, Return Loss 50 to 60 dB, Attenuation Tolerance ±0.5 dB, Polarization Dependent Loss 0.1 dB, Operating Wavelength 1310 nm, 1550 nm. More details for V3100-S can be seen below.