diff --git a/adafruit_platformdetect/board.py b/adafruit_platformdetect/board.py
index 6690fbc..872435d 100644
--- a/adafruit_platformdetect/board.py
+++ b/adafruit_platformdetect/board.py
@@ -896,6 +896,8 @@ def _rp2040_u2if_id(self) -> Optional[str]:
             product = dev["product_id"]
             if vendor == 0xCAFE and product == 0x4005:
                 return boards.PICO_U2IF
+            if vendor == 0xCAFF and product == 0x4005:
+                return boards.RADXA_X4_U2IF
             if vendor == 0x239A:
                 # Feather RP2040
                 if product == 0x00F1:
@@ -1203,6 +1205,7 @@ def lazily_generate_conditions():
             yield self.board.QT2040_TRINKEY_U2IF
             yield self.board.KB2040_U2IF
             yield self.board.RP2040_ONE_U2IF
+            yield self.board.RADXA_X4_U2IF
             yield self.board.OS_AGNOSTIC_BOARD
 
         return any(condition for condition in lazily_generate_conditions())
@@ -1342,6 +1345,11 @@ def rp2040_one_u2if(self) -> bool:
         """Check whether the current board is an RP2040 One w/ u2if."""
         return self.id == boards.RP2040_ONE_U2IF
 
+    @property
+    def radxa_x4_u2if(self) -> bool:
+        """Check whether the current board is an RP2040 One w/ u2if."""
+        return self.id == boards.RADXA_X4_U2IF
+
     @property
     def binho_nova(self) -> bool:
         """Check whether the current board is an BINHO NOVA."""
diff --git a/adafruit_platformdetect/chip.py b/adafruit_platformdetect/chip.py
index e3d950e..0eba6bc 100644
--- a/adafruit_platformdetect/chip.py
+++ b/adafruit_platformdetect/chip.py
@@ -125,7 +125,8 @@ def id(
                     if (
                         (
                             # Raspberry Pi Pico
-                            vendor == 0xCAFE
+                            # Radxa X4
+                            vendor in (0xCAFE, 0xCAFF)
                             and product == 0x4005
                         )
                         or (
diff --git a/adafruit_platformdetect/constants/boards.py b/adafruit_platformdetect/constants/boards.py
index f5024f2..de34414 100644
--- a/adafruit_platformdetect/constants/boards.py
+++ b/adafruit_platformdetect/constants/boards.py
@@ -195,6 +195,7 @@
 KB2040_U2IF = "KB2040_U2IF"
 
 RP2040_ONE_U2IF = "RP2040_ONE_U2IF"
+RADXA_X4_U2IF = "RADXA_X4_U2IF"
 
 BINHO_NOVA = "BINHO_NOVA"