@zvoz 

Hey

As the device is a tad older now, it only supports Passive POE and therefore will require an injector to work correctly (1x injector for each AP)

In terms of what specific model, anything with 15watts or more should work with this AP.  

  @Philbert 

Thank you, what about Voltage, does it need to be 9V?

Thank you

  @zvoz 

Yes 9v POE would be perfect for this, however thats not a common standard anymore as the standards are based around 12v.   9v injectors are available, but sadly not that common and a bit more pricey.

Just thinking out loud here, the WA901N is a older device now.   You may find it more feasible to upgrade the device and get the benefit of the 5ghz frequency and speeds.    For example in Ireland here the WA1201 Access Point is €40 and comes with an injector, its going to cost €20 for the older injector alone.    €40 more for 2x newer, faster APs seems like a better deal all round mate

You are literally talking 3x times the speed increase and a good jump in futureproofing

  @zvoz Thank you