Fiber optic attenuators are devices used to reduce or monitor the power level of a fiber optic signal. Basic types of fixed attenuation include single mode, dual window and multimode in D4/PC, FC, FC/UPC, MU, SC, SC/APC and UPC, ST and ST/UPC style connectors. We offer SM and PM electronic VOAs that provide control of the output power with FC/PC or FC/APC connectors. Farnell® Germany offers fast quotes, same day dispatch, fast delivery, wide inventory, datasheets & technical support. The input of the attenuator has a 2. 2 mm wide key female connector, making it compatible with.