The Nanobridge M5 feeder requires a power over Ethernet (PoE) power source. There are a few options for powering the Nanobridge M5:

1. Use a PoE injector: 

This is a simple device that injects power into an Ethernet cable. You just connect the injector to a power source, connect one end of an Ethernet cable to the injector and the other end to the Nanobridge M5, and it will power the device. Ubiquiti, the maker of Nanobridge, sells PoE injectors that will work well.

2. Use a PoE switch: 

A PoE switch is a network switch that also provides PoE power to connected devices like the Nanobridge M5. You just connect the Nanobridge to one of the PoE ports on the switch using an Ethernet cable, and it will power the device. Ubiquiti also sells PoE switches that work great for powering their equipment.

3. Use a power supply with a barrel connector: 

The Nanobridge M5 also has a port for connecting a power supply directly. 

You just need a 12V power supply with a 5.5mm x 2.1mm barrel connector. 

Connect the power supply to the Nanobridge M5 and it will power the device.

 You'll still need an Ethernet cable connected to provide the network connectivity.

4. Power over the air: 

If no power source is available nearby, the Nanobridge M5 can actually be powered over the air by another Nanobridge M5 device. 

You need to enable the Power over Air feature on both Nanobridge radios, align them properly, and one can actually power the other over the wireless link.

So in summary, the main options are:

1. PoE Injector 

2. PoE Switch

3. 12V Power Supply (w/barrel connector)

4. Power over Air (using another Nanobridge M5)

Hope this helps! Let me know if you have any other questions.