diff --git a/src/pals/kinds/Marker.py b/src/pals/kinds/Marker.py
index 649f5f3..4d864a0 100644
--- a/src/pals/kinds/Marker.py
+++ b/src/pals/kinds/Marker.py
@@ -1,9 +1,9 @@
 from typing import Literal
 
-from .mixin import ThinElement
+from .mixin import BaseElement
 
 
-class Marker(ThinElement):
+class Marker(BaseElement):
     """Zero length element to mark a particular position
 
     The main purpose of this thin element is to name a position in the beamline.
@@ -11,3 +11,7 @@ class Marker(ThinElement):
 
     # Discriminator field
     kind: Literal["Marker"] = "Marker"
+
+    # Segment length in meters (m)
+    # Always 0, cannot be modified
+    length: Literal[0.0] = 0.0
diff --git a/src/pals/kinds/mixin/ThickElement.py b/src/pals/kinds/mixin/ThickElement.py
index 1780566..e8dfffb 100644
--- a/src/pals/kinds/mixin/ThickElement.py
+++ b/src/pals/kinds/mixin/ThickElement.py
@@ -1,5 +1,5 @@
 from typing import Annotated, Literal
-from annotated_types import Gt
+from annotated_types import Ge
 
 from . import BaseElement
 
@@ -11,4 +11,4 @@ class ThickElement(BaseElement):
     kind: Literal["ThickElement"] = "ThickElement"
 
     # Segment length in meters (m)
-    length: Annotated[float, Gt(0)]
+    length: Annotated[float, Ge(0)]
diff --git a/src/pals/kinds/mixin/ThinElement.py b/src/pals/kinds/mixin/ThinElement.py
deleted file mode 100644
index 1981bf3..0000000
--- a/src/pals/kinds/mixin/ThinElement.py
+++ /dev/null
@@ -1,14 +0,0 @@
-from typing import Literal
-
-from . import BaseElement
-
-
-class ThinElement(BaseElement):
-    """A thin base element with zero segment length"""
-
-    # Discriminator field
-    kind: Literal["ThinElement"] = "ThinElement"
-
-    # Segment length in meters (m)
-    # always 0 for thin elements, not modifiable
-    length: Literal[0.0] = 0.0
diff --git a/src/pals/kinds/mixin/__init__.py b/src/pals/kinds/mixin/__init__.py
index cf1687a..3c9fb3d 100644
--- a/src/pals/kinds/mixin/__init__.py
+++ b/src/pals/kinds/mixin/__init__.py
@@ -1,3 +1,2 @@
 from .BaseElement import BaseElement  # noqa: F401
 from .ThickElement import ThickElement  # noqa: F401
-from .ThinElement import ThinElement  # noqa: F401