ASROCK B550 Phantom Gaming 4 Manual page 200

Operations in the 5.15-5.35GHz band are restricted to indoor usage only.
Radio transmit power per transceiver type
Function
WiFi
Bluetooth
Frequency
2400-2483.5 MHz
5150-5250 MHz
5250-5350 MHz
5470-5725 MHz
2400-2483.5 MHz
Maximum Output Power (EIRP)
18.5 + / -1.5 dbm
21.5 + / -1.5 dbm
18.5 + / -1.5 dbm (no TPC)
21.5 + / -1.5 dbm (TPC)
25.5 + / -1.5 dbm (no TPC)
28.5 + / -1.5 dbm (TPC)
8.5 + / -1.5 dbm