Narrowband Filter Module Bandpass RF Rectifier Fit for CW or SSB Mode Radio Communication Accessories Condition: Item Type: Narrowband Pass Filter ModuleMaterial: Printed Circuit Board Color: As the Picture ShownInstallation: Two installation positions (817a) of the filter, one side is four pins and the other side is three pins. After the pins are aligned according to the filter screen, close the machine, open the machine cover, you can see the plug . After installing the power supply, you can filter in the opened menu. If 1K and 2.7K filters are purchased at the same time, they can be identified by the characters printed on the filter. The CFJ455K8 model is 1K with a filter; CFJ455K13 is 2.7 K, regardless of the installation time slot, two slots can be It's easy to reverse it, after installation, you can identify your machine is 1 K, which is 2.7K.