The Fixed-SM Series from Huihong Technologies Limited is a Fiber Optic Attenuator with Attenuation 1 to 30 dB, Operating Temperature -40 to 75 Degree C, Optical Power w 1 W, Return Loss 55 dB(UPC), 65 Db(APC), Wavelength 1260nm - 1620 nm. More details for Fixed-SM Series can be seen below.