diff --git a/src/pyxems/csx.py b/src/pyxems/csx.py
index bc4900f..8402f7c 100644
--- a/src/pyxems/csx.py
+++ b/src/pyxems/csx.py
@@ -1,5 +1,5 @@
 from dataclasses import dataclass, field
-from typing import Literal, get_args, Protocol
+from typing import Literal, get_args, Protocol, Optional
 
 Axes = Literal["X", "Y", "Z"]
 
@@ -34,7 +34,7 @@ def __str__(self, short=True) -> str:
 
 
 @dataclass()
-class Material:
+class MaterialProperty:
     name: str
     epsilon_r: Physical
     mu_r: Physical
@@ -49,6 +49,22 @@ def to_xml(self, short=True) -> str:
             return f'<{self.name} Epsilon="{self.epsilon_r.__str__(short=False)}" Mue="{self.mu_r.__str__(short=False)}" Kappa="{self.kappa.__str__(short=False)}" Sigma="{self.sigma.__str__(short=False)}" Density="{self.density:e}" />'
 
 
+@dataclass
+class LumpedProperty:
+    direction: Optional[Axes] = "Z"
+    caps: int = 1
+    resistance: float = 50
+    capacitance: float = 0
+    inductance: float = 0
+    letype: int = 0
+
+    def to_xml(self, short=True) -> str:
+        axe_number = {"X": 0, "Y": 1, "Z": 2}
+        cap = self.capacitance if self.capacitance != 0 else "-nan(ind)"
+        ind = self.inductance if self.inductance != 0 else "-nan(ind)"
+        return f' Direction="{axe_number[self.direction]}" Caps="{self.caps}" R="{self.resistance:e}" C="{cap}" L="{ind}" LEtype="{self.letype:e}"'
+
+
 @dataclass(frozen=True)
 class Color:
     r: int
@@ -81,18 +97,25 @@ def to_xml(self) -> str:
         return xml
 
 
+PropertyKind = Literal[
+    "Metal", "Material", "LumpedElement", "Excitation", "ProbeBox", "DumpBox"
+]
+
+
 @dataclass(frozen=True)
 class Property:
     name: str
     id: int
-    kind: Literal["Metal", "Material"] = "Material"
+    kind: PropertyKind = "Material"
     fillcolor: Color = field(default_factory=lambda: Color(255, 255, 255, 255))
     edgecolor: Color = field(default_factory=lambda: Color(0, 0, 0, 255))
-    material: Material = field(
-        default_factory=lambda: Material("Property", Physical(1.0), Physical(1.0))
+    material: MaterialProperty | LumpedProperty = field(
+        default_factory=lambda: MaterialProperty(
+            "Property", Physical(1.0), Physical(1.0)
+        )
     )
-    weight: Material = field(
-        default_factory=lambda: Material(
+    weight: MaterialProperty = field(
+        default_factory=lambda: MaterialProperty(
             "Weight",
             Physical(1.0),
             Physical(1.0),
@@ -104,7 +127,13 @@ class Property:
     _primitive: list[Primitive] = field(default_factory=list)
 
     def to_xml(self) -> str:
-        iso = ' Isotropy="1"' if self.kind == "Material" else ""
+        match self.kind:
+            case "Metal":
+                iso = ""
+            case "Material":
+                iso = ' Isotropy="1"'
+            case "LumpedElement":
+                iso = self.material.to_xml()
         xml = f'<{self.kind} ID="{self.id}" Name="{self.name}"{iso}>\n'
         xml += f"    <FillColor {self.fillcolor.to_xml()} />\n"
         xml += f"    <EdgeColor {self.edgecolor.to_xml()} />\n"
@@ -124,8 +153,8 @@ def to_xml(self) -> str:
 class ContinousStructure:
     coordinates_system: int = 0
     lines: dict[Axes, Line] = field(default_factory=dict)
-    background_material: Material = field(
-        default_factory=lambda: Material(
+    background_material: MaterialProperty = field(
+        default_factory=lambda: MaterialProperty(
             "BackgroundMaterial", Physical(1.0), Physical(1.0)
         )
     )
@@ -140,29 +169,33 @@ def add_line(self, axe: Axes, position: float):
 
     def add_property(
         self,
-        kind: Literal["Metal", "Material"],
+        kind: PropertyKind,
         name: str,
         fillcolor: Color = Color(255, 255, 255, 255),
-        edgecolor: Color = Color(0, 0, 0, 255),
+        edgecolor: Optional[Color] = None,
         eps: float = 1.0,
         mu: float = 1.0,
         kappa: float = 0.0,
         sigma: float = 0.0,
     ):
         id = len(self.properties)
-        prop = Property(
-            name,
-            id,
-            kind,
-            fillcolor,
-            edgecolor,
-            material=Material(
+        if kind in ("Material", "Metal"):
+            property = MaterialProperty(
                 "Property",
                 Physical(eps),
                 Physical(mu),
                 Physical((kappa, 0, 0)),
                 Physical((sigma, 0, 0)),
-            ),
+            )
+        else:
+            property = LumpedProperty()
+        prop = Property(
+            name,
+            id,
+            kind,
+            fillcolor,
+            edgecolor if edgecolor is not None else fillcolor,
+            material=property,
         )
         self.properties.append(prop)
 
diff --git a/tests/test_main.py b/tests/test_main.py
index 1a9ed1e..692a4fe 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -193,5 +193,12 @@ def test_generate_simp_patch(tmp_path: Path):
         priority=10,
         property_id=2,
     )
+    oems_config.csx.add_property("LumpedElement", "port_resist_1", Color(144, 73, 241))
+    oems_config.csx.add_box(
+        start=(-6, 0, 0),
+        stop=(-6, 0, 1.524),
+        priority=5,
+        property_id=3,
+    )
     write_openEMS_xml(tmp_path / "openEMS_config.xml", oems_config)
     assert (tmp_path / "openEMS_config.xml").read_text() == ref.read_text()