The JDS Uniphase VA4 Series Manual Variable Attenuators are compact, portable instruments for field system testing as well as test and development in laboratory applications. They provide continuously variable attenuation range of up to 65 dB with calibration wavelengths of 830/1300 nm or 1300/1550 nm. Attenuation is set manually from the front panel at a 0.1 dB resolution. Unlike programmable attenuators, the attenuation level is maintained when the power is turned on or off. The attenuators use JDS Uniphase's ultra-linear attenuator prism and highly reliable microlense technology to produce accurate attenuation settings with low insertion loss and excellent return loss.