FC-PC, FC-APC Type Universal Adapter OLS-3x OLS & OCC-55/56
    Ferrule Diameter 2.5 mm
    Accurate power measurements with built-in reflection trap

JDSU VIAVI 2150/00.51 Fiber Optic FC-PC, FC-APC Type Universal Adapter is used on the OCC-55 CWDM and OCC-56C DWDM Smart Optical Channel Checkers and the OLS34, OLS-35 & OLS-36 Optical Light Sources with the interchangeable adapter. This optional adapter cap is used to make your meter adapt to ST fiber optic connectors.

Like new, just not in original packaging.