/> This handheld optical variable attenuator, model 5501, features low battery power indication, on line attenuation, and stepwise attenuation of 0.05dB steps. The attenuation has a wide measurement range from 2.5dB to 65Db and an attenuating wavelength range from 1260nm to 1650nm at an accuracy of ±0.8dB. Calibrated wavelengths of 1310, 1490, 1550 and 1625nm are available. Equipped with a LCD, it can display wavelength, input power, output power, current attenuation and selected step size and absolute and relative attenuation value simultaneously. Moreover, this attenuator not only combines the functions of both an attenuator and an optical power meter but also boasts optical Auto-off function.