[POE] IEEE 802.3af VS 802.11b

Hello,
Today I receive this adaptator for my Arduino Ethernet Poe. When I plugged it, an explosion happened and smoke appeared. I don't understand why.
Is it because Arduino is "IEEE802.3af" and this injector is "802.11b" ?

Thanks a lot.

Probably got more to do with the fact that it's a 48 volt power supply. What is the maximum recommended input of the board you have? 12 volts?

36V to 57V.