diff --git a/src/mercury_engine_data_structures/formats/__init__.py b/src/mercury_engine_data_structures/formats/__init__.py
index 07c4d582..be39e0ea 100644
--- a/src/mercury_engine_data_structures/formats/__init__.py
+++ b/src/mercury_engine_data_structures/formats/__init__.py
@@ -16,6 +16,7 @@
 from mercury_engine_data_structures.formats.bmsnav import Bmsnav
 from mercury_engine_data_structures.formats.bmssd import Bmssd
 from mercury_engine_data_structures.formats.bmtre import Bmtre
+from mercury_engine_data_structures.formats.bmtun import Bmtun
 from mercury_engine_data_structures.formats.brem import Brem
 from mercury_engine_data_structures.formats.bres import Bres
 from mercury_engine_data_structures.formats.brev import Brev
@@ -41,6 +42,7 @@
     "BMSSS": Bmsss,
     "BMSAD": Bmsad,
     "BMSAS": Bmsas,
+    "BMTUN": Bmtun,
     "BRFLD": Brfld,
     "BMSCC": Bmscc,
     "BMSCD": Bmscc,
diff --git a/src/mercury_engine_data_structures/formats/bmtun.py b/src/mercury_engine_data_structures/formats/bmtun.py
new file mode 100644
index 00000000..905ee0dc
--- /dev/null
+++ b/src/mercury_engine_data_structures/formats/bmtun.py
@@ -0,0 +1,55 @@
+import functools
+
+import construct
+from construct.core import (
+    Array,
+    Const,
+    Construct,
+    Flag,
+    Float32l,
+    Hex,
+    Int32sl,
+    Int32ul,
+    Struct,
+    Switch,
+)
+
+from mercury_engine_data_structures.common_types import Char, Float, StrId, make_dict
+from mercury_engine_data_structures.construct_extensions.misc import ErrorWithMessage
+from mercury_engine_data_structures.formats import BaseResource
+from mercury_engine_data_structures.game_check import Game
+
+# Functions
+TunableParam = Struct(
+    type=Char,
+    value=Switch(
+        construct.this.type,
+        {
+            's': StrId,
+            'f': Float,
+            'b': Flag,
+            'i': Int32sl,
+            'v': Array(3, Float32l)
+        },
+        ErrorWithMessage(lambda ctx: f"Unknown argument type: {ctx.type}", construct.SwitchError)
+    )
+)
+
+TunableClass = Struct(
+    "tunables" / make_dict(TunableParam),
+)
+
+# BMTUN
+BMTUN = Struct(
+    "_magic" / Const(b"MTUN"),
+    "version" / Const(0x00050001, Hex(Int32ul)),
+    "classes" / make_dict(TunableClass),
+    construct.Terminated,
+)
+
+
+class Bmtun(BaseResource):
+    @classmethod
+    @functools.lru_cache
+    def construct_class(cls, target_game: Game) -> Construct:
+        return BMTUN
diff --git a/tests/formats/test_bmtun.py b/tests/formats/test_bmtun.py
new file mode 100644
index 00000000..1491796e
--- /dev/null
+++ b/tests/formats/test_bmtun.py
@@ -0,0 +1,13 @@
+import pytest
+from tests.test_lib import parse_build_compare_editor
+
+from mercury_engine_data_structures import samus_returns_data
+from mercury_engine_data_structures.formats.bmtun import Bmtun
+
+all_sr_bmtun = [name for name in samus_returns_data.all_name_to_asset_id().keys()
+                   if name.endswith(".bmtun")]
+
+
+@pytest.mark.parametrize("bmtun_path", all_sr_bmtun)
+def test_bmtun(samus_returns_tree, bmtun_path):
+    parse_build_compare_editor(Bmtun, samus_returns_tree, bmtun_path)