Received the Ubiquiti INS-3AF-I-G earlier today (TY Amazon). On the box and unit it clearly states 24Volts so no idea where the 48 comes from in the description.
Did some quick metering and checking and dropped it in, WORKS GREAT!
It is not the cheapest alternative out there but I can confirm that it works with Full Gigabit support and does not drop down to 100 and with that I am more than happy to have paid the £22 for it especially as I had it within 12 hours lol.
So anyone looking to get POE to any of the units from a POE Switch (3af or 3at) then this little gizmo does the job out the box. No faffing about wiring your own cables, using injectors or looking to replace the switch to one that has a Passive override (like I nearly did).