The DA-100-3S-850-50/125-M-35 from OZ Optics Ltd. is a Fiber Optic Attenuator with Wavelength Dependent Loss Up to 0.3 dB (Attenuation), Attenuation 1 to 40 dB, Attenuation Resolution 0.01 dB, Insertion Loss 2 to 4 dB, Return Loss 35 dB. More details for DA-100-3S-850-50/125-M-35 can be seen below.