The FITB39259KBN | AT-F-FCU from Fiberinthebox is a Fiber Optic Attenuator with Attenuation 1 to 25 dB, Return Loss 55 dB, Polarization Dependent Loss Less than 0.2 dB, Operating Wavelength 1310 nm, 1550 nm (Single Mode), 850 nm, 1300 nm (Multi Mode), Optical Input Power 200 mW. More details for FITB39259KBN | AT-F-FCU can be seen below.