The MPS-2550 from Microwave Photonic Systems is a Fiber Optic Attenuator with Attenuation 35.0 dB, Attenuation Resolution 0.01 dB to 0.2 dB, Insertion Loss 0.5 dB (intrinsic), Operating Temperature -40 to 85 Degree C, Return Loss -45 dB. More details for MPS-2550 can be seen below.