diff --git a/README.md b/README.md
index 63a15d9..68df7fa 100644
--- a/README.md
+++ b/README.md
@@ -28,4 +28,7 @@ switch.off()
 Obtaining the key
 -----------------
 
-Obtain the key by holding the down button on the switch until the green light flashes, and then run the get_key script.
\ No newline at end of file
+Obtain the key by holding the down button on the switch until the green light flashes, and then run the get_key script.
+
+**Noted on firmware 6.4**: `get_key.py` may not work on firmware version 6.4 as the key changing process is updated. However,
+if you are able to get the key manually (e.g. from BLE sniffering), the library should still expect to work.
diff --git a/decora/__init__.py b/decora/__init__.py
index 2a62261..22cf996 100644
--- a/decora/__init__.py
+++ b/decora/__init__.py
@@ -84,7 +84,7 @@ def get_event(self, event):
       raise decoraException("Unable to get event")
 
   def set_event(self, event, data):
-    packet = bytearray([0x11, event, data[0], data[1], data[2], data[3]])
+    packet = bytearray([0x11, event, *data])
     try:
       self.device.writeCharacteristic(self.handles["event"], packet, withResponse=True)
     except btle.BTLEException:
diff --git a/docs/decora-ble-v6.4.md b/docs/decora-ble-v6.4.md
new file mode 100644
index 0000000..826f412
--- /dev/null
+++ b/docs/decora-ble-v6.4.md
@@ -0,0 +1,51 @@
+# Protocol for firmware 6.4
+
+## Test environment:
+
+- **Device**: Leviton Decora DDMX1
+- **Version**: 6.4
+- **Datetime**: Aug. 7, 2021
+
+## Descriptions
+
+The fireware version `6.4` seems to change the key changing process.
+
+Currently, there is an mistery byte appending to the KEY sent from Decora BLE pairing mode.
+
+The actually KEY is now -
+
+Say we have `KEY_FROM_BLE`, which is (still) four byte long.
+The actually `KEY` - which to be sent to BLE for authentication - is the `KEY_FROM_BLE` appended by
+the `THE_MISTRIOUS_BYTE`, it's five bytes long. i.e.,
+
+KEY = KEY_FROM_BLE + THE_MISTRIOUS_BYTE
+
+
+The captured traffic on the ATT stack around the auth (Handle 0x37, or "event"):
+
+>
+> 1. ...Auth starts
+> 
+> 1. Localhost -> BLE
+>    Request Write: `0x37`, Value: _22 53 00 00 00 00 00_
+>    
+> 1. Localhost -> BLE
+>    Request Read: `0x37`
+>    Response: _22 53 **81 46 5C 76** 00_
+>    
+> 1. Localhost -> BLE
+>    Request Write: `0x37`, Value: _22 53 **81 46 5C 76** 67_    
+> 
+> 1. Auth completes...  
+>
+
+In the above traffic sample,
+`KEY_FROM_BLE`=`81 46 5C 76` (or `81 46 5C 76 00`)
+`THE_MISTRIOUS_BYTE`=`0x67`
+`KEY`=`81 46 5C 76 67`
+
+Noted that, on the current Decora mobile app UI (both iOS and Android), the user can reset the current authentication and
+re-authenticate. This will change the `KEY_FROM_BLE` as well as the `THE_MISTRIOUS_BYTE`. This will de-auth all the paired
+devices.
+
+![Screenshot to de-auth device](./deauth.png)
diff --git a/docs/images/deauth.png b/docs/images/deauth.png
new file mode 100644
index 0000000..a3ed0d9
Binary files /dev/null and b/docs/images/deauth.png differ
diff --git a/setup.py b/setup.py
index e5a29ab..bc9378a 100644
--- a/setup.py
+++ b/setup.py
@@ -12,7 +12,7 @@
 
 setup(
     name='decora',
-    version=0.6,
+    version=0.7,
     author='Matthew Garrett',
     author_email='mjg59@srcf.ucam.org',
     url='http://github.com/mjg59/python-decora',