diff --git a/ttn-gps-mapper-abp.ino b/ttn-gps-mapper-abp.ino
index 18d1a5f..a071a45 100644
--- a/ttn-gps-mapper-abp.ino
+++ b/ttn-gps-mapper-abp.ino
@@ -37,8 +37,9 @@
 
 
     //mapper-bb-006 please insert the keys in MSB Format 
+    // DEVADDR example: 260A1B2C
 
-    static const u4_t DEVADDR = 0x260XXXX;
+    static const u4_t DEVADDR = 0x260XXXXX;
     static const u1_t PROGMEM APPSKEY[16]={ XXX };
     static const u1_t PROGMEM NWKSKEY[16]={ XXX };
 
@@ -250,4 +251,4 @@
           Serial.println("no GPS fix");
         }
      }
-    }
\ No newline at end of file
+    }