This 4db SC APC fiber optic attenuator is fixed.
It has a SC simplex male on one end and a SC simplex female on the other end. For instance it’s typically used for either testing power levels or reducing power levels of an optical signal.
Single mode SC fiber optic attenuators typically fit 1310nm and 1550nm
single mode fiber applications. In fact attenuation range is from 1dB to 30dB.
When attenuators are used inline the optical power light in the systems for both lab and commercial applications is reduced.