The 1G02259 Mounting Bracket is used to connect round photodiode sensors to a fiber adapter (SC, ST, FC or SMA). This bracket can be used for the PD300R (round) photodiode series, as well as the FPS-1 fast photodiode. It is not needed for the PD300-IRG sensor. This bracket is also used for mounting ND attenuators on the FPS-1.