... -a-c-da: Operating Wavelength, a=1310 for 1310nm, a=1315 for 1310 and 1550nm dual wavelengths, etc. C: Variable Optical Attenuator(VOA ... -a-c-da: Operating Wavelength, a=1310 for 1310nm, a=1315 for 1310 and 1550nm dual wavelengths, etc. C: Pigtail Type, c=3 ... for 3mm jacket pigtail, etc. D: Connector Type, d=FA for FC/APC ...