The C Band MEMS VOA 1530-1570nm from OF-Link Communications is a Fiber Optic Attenuator with Wavelength Dependent Loss 0.3 to 1.5 dB, Attenuation 30 dB, 40 dB (Blocking State Attenuation (Dark Type), Insertion Loss 0.5 to 0.7 dB, Return Loss 45 dB, Polarization Dependent Loss 0.1 to 0.3 dB. More details for C Band MEMS VOA 1530-1570nm can be seen below.