Hmmm, that is strange, I just looked and my 215s, 225s and even the 325s show the same markings, but strangely, only the 325 shows 450mA where the 225s show 350mA like the 215s do.
I assume they are implying the MAX voltage that can be used on POE for these devices as their respective spec sheets all show 48V.
As you can see, the existing POE injector is working so you should be fine.
I can honestly say I have never really noticed that label on the back of the AP before.
Considering that all the APs adhere to 802.3af or 802.3at requirements and standards, depending on the model, then they are probably just putting the max value on the AP.
Excerpt from IEEE on 802.3 below, showing a voltage range of 37-57V depending on the type.
PoE vs PoE+ parameters Property 802.3af (802.3at Type 1) "PoE" 802.3at Type 2 "PoE+"
Power available at PD[note 1] | 12.95 W | 25.50 W |
Maximum power delivered by PSE | 15.40 W | 30.0 W |
Voltage range (at PSE) | 44.0–57.0 V[21] | 50.0–57.0 V[21] |
Voltage range (at PD) | 37.0–57.0 V[22] | 42.5–57.0 V[22] |
Maximum current | 350 mA[23] | 600 mA[23] per mode |
Maximum cable resistance | 20 Ω[24] (Category 3) | 12.5 Ω[24] (Category 5) |
Power management | Three power class levels negotiated at initial connection | Four power class levels negotiated at initial connection or 0.1 W steps negotiated continuously |
Derating of maximum cable ambient operating temperature | None | 5 °C (9 °F) with one mode (two pairs) active |
Supported cabling | Category 3 and Category 5[1] | Category 5[1][note 2] |
Supported modes | Mode A (endspan), Mode B (midspan) | Mode A, Mode B |
Chris