"Agilent 81578A-062 Agilent/HP 81578A Variable Optical Attenuator Module for Multimode Fiber Applications The Agilent 81578A variable optical attenuator is designed for multimode fiber applications and features lowest insertion loss and excellent wavelength flatness over a complete attenuation range of 60 dB, for characterizing optical network components for telecomunication and data communication in systems."