diff --git a/bumble/core.py b/bumble/core.py
index 2722b870..5bbddd0b 100644
--- a/bumble/core.py
+++ b/bumble/core.py
@@ -821,8 +821,8 @@ def __init__(self, ad_structures: Optional[List[Tuple[int, bytes]]] = None) -> N
             ad_structures = []
         self.ad_structures = ad_structures[:]
 
-    @staticmethod
-    def from_bytes(data):
+    @classmethod
+    def from_bytes(cls, data: bytes) -> AdvertisingData:
         instance = AdvertisingData()
         instance.append(data)
         return instance
@@ -978,7 +978,7 @@ def ad_data_to_object(ad_type: int, ad_data: bytes) -> AdvertisingObject:
 
         return ad_data
 
-    def append(self, data):
+    def append(self, data: bytes) -> None:
         offset = 0
         while offset + 1 < len(data):
             length = data[offset]
diff --git a/bumble/device.py b/bumble/device.py
index 6d5c00c8..3d4b59a2 100644
--- a/bumble/device.py
+++ b/bumble/device.py
@@ -243,16 +243,40 @@
 
 
 # -----------------------------------------------------------------------------
+@dataclass
 class Advertisement:
+    # Attributes
     address: Address
-
-    TX_POWER_NOT_AVAILABLE = (
+    rssi: int = HCI_LE_Extended_Advertising_Report_Event.RSSI_NOT_AVAILABLE
+    is_legacy: bool = False
+    is_anonymous: bool = False
+    is_connectable: bool = False
+    is_directed: bool = False
+    is_scannable: bool = False
+    is_scan_response: bool = False
+    is_complete: bool = True
+    is_truncated: bool = False
+    primary_phy: int = 0
+    secondary_phy: int = 0
+    tx_power: int = (
         HCI_LE_Extended_Advertising_Report_Event.TX_POWER_INFORMATION_NOT_AVAILABLE
     )
-    RSSI_NOT_AVAILABLE = HCI_LE_Extended_Advertising_Report_Event.RSSI_NOT_AVAILABLE
+    sid: int = 0
+    data_bytes: bytes = b''
+
+    # Constants
+    TX_POWER_NOT_AVAILABLE: ClassVar[
+        int
+    ] = HCI_LE_Extended_Advertising_Report_Event.TX_POWER_INFORMATION_NOT_AVAILABLE
+    RSSI_NOT_AVAILABLE: ClassVar[
+        int
+    ] = HCI_LE_Extended_Advertising_Report_Event.RSSI_NOT_AVAILABLE
+
+    def __post_init__(self) -> None:
+        self.data = AdvertisingData.from_bytes(self.data_bytes)
 
     @classmethod
-    def from_advertising_report(cls, report):
+    def from_advertising_report(cls, report) -> Optional[Advertisement]:
         if isinstance(report, HCI_LE_Advertising_Report_Event.Report):
             return LegacyAdvertisement.from_advertising_report(report)
 
@@ -261,41 +285,6 @@ def from_advertising_report(cls, report):
 
         return None
 
-    # pylint: disable=line-too-long
-    def __init__(
-        self,
-        address,
-        rssi=HCI_LE_Extended_Advertising_Report_Event.RSSI_NOT_AVAILABLE,
-        is_legacy=False,
-        is_anonymous=False,
-        is_connectable=False,
-        is_directed=False,
-        is_scannable=False,
-        is_scan_response=False,
-        is_complete=True,
-        is_truncated=False,
-        primary_phy=0,
-        secondary_phy=0,
-        tx_power=HCI_LE_Extended_Advertising_Report_Event.TX_POWER_INFORMATION_NOT_AVAILABLE,
-        sid=0,
-        data=b'',
-    ):
-        self.address = address
-        self.rssi = rssi
-        self.is_legacy = is_legacy
-        self.is_anonymous = is_anonymous
-        self.is_connectable = is_connectable
-        self.is_directed = is_directed
-        self.is_scannable = is_scannable
-        self.is_scan_response = is_scan_response
-        self.is_complete = is_complete
-        self.is_truncated = is_truncated
-        self.primary_phy = primary_phy
-        self.secondary_phy = secondary_phy
-        self.tx_power = tx_power
-        self.sid = sid
-        self.data = AdvertisingData.from_bytes(data)
-
 
 # -----------------------------------------------------------------------------
 class LegacyAdvertisement(Advertisement):
@@ -319,7 +308,7 @@ def from_advertising_report(cls, report):
             ),
             is_scan_response=report.event_type
             == HCI_LE_Advertising_Report_Event.SCAN_RSP,
-            data=report.data,
+            data_bytes=report.data,
         )
 
 
@@ -344,7 +333,7 @@ def from_advertising_report(cls, report):
             secondary_phy    = report.secondary_phy,
             tx_power         = report.tx_power,
             sid              = report.advertising_sid,
-            data             = report.data
+            data_bytes       = report.data
         )
         # fmt: on
 
@@ -405,7 +394,7 @@ class AdvertisingType(IntEnum):
     # fmt: on
 
     @property
-    def has_data(self):
+    def has_data(self) -> bool:
         return self in (
             AdvertisingType.UNDIRECTED_CONNECTABLE_SCANNABLE,
             AdvertisingType.UNDIRECTED_SCANNABLE,
@@ -413,7 +402,7 @@ def has_data(self):
         )
 
     @property
-    def is_connectable(self):
+    def is_connectable(self) -> bool:
         return self in (
             AdvertisingType.UNDIRECTED_CONNECTABLE_SCANNABLE,
             AdvertisingType.DIRECTED_CONNECTABLE_HIGH_DUTY,
@@ -421,14 +410,14 @@ def is_connectable(self):
         )
 
     @property
-    def is_scannable(self):
+    def is_scannable(self) -> bool:
         return self in (
             AdvertisingType.UNDIRECTED_CONNECTABLE_SCANNABLE,
             AdvertisingType.UNDIRECTED_SCANNABLE,
         )
 
     @property
-    def is_directed(self):
+    def is_directed(self) -> bool:
         return self in (
             AdvertisingType.DIRECTED_CONNECTABLE_HIGH_DUTY,
             AdvertisingType.DIRECTED_CONNECTABLE_LOW_DUTY,