diff --git a/src/application/ElementService.js b/src/application/ElementService.js
index 995fb03..456dfa1 100644
--- a/src/application/ElementService.js
+++ b/src/application/ElementService.js
@@ -88,4 +88,20 @@ export class ElementService {
         const newY = Math.round(x * sin + y * cos);
         return [newX, newY];
     }
+
+    /**
+     * Updates properties of an element.
+     * 
+     * @param {Element} element - The element whose properties are being updated.
+     * @param {Object} updates - An object containing property updates.
+     * @throws {Error} If any property value is invalid.
+     */
+    static updateProperties(element, updates) {
+        Object.entries(updates).forEach(([key, value]) => {
+            if (!element.properties.isValidValue(value)) {
+                throw new Error(`Invalid value for property "${key}". Must be a float, "variable", or "undefined".`);
+            }
+            element.properties.values[key] = value;
+        });
+    }
 }
diff --git a/src/domain/valueObjects/Properties.js b/src/domain/valueObjects/Properties.js
index 5f367f5..830e656 100644
--- a/src/domain/valueObjects/Properties.js
+++ b/src/domain/valueObjects/Properties.js
@@ -6,13 +6,45 @@ export class Properties {
      * Creates a properties container.
      * 
      * @param {Object} values - An object containing the value objects for the properties.
+     * @throws {Error} If any value is invalid.
      */
     constructor(values = {}) {
-        if (typeof values !== 'object') {
-            throw new Error("Properties must be an object.");
+        if (typeof values !== 'object' || values === null) {
+            throw new Error("Properties must be a non-null object.");
         }
 
-        this.values = values; // Store value objects (e.g., Resistance, Capacitance)
+        // Validate each property value
+        Object.entries(values).forEach(([key, value]) => {
+            if (!this.isValidValue(value)) {
+                throw new Error(`Invalid value for property "${key}". Must be a float, "variable", or "undefined".`);
+            }
+        });
+
+        this.values = values; // Store valid values
+    }
+
+    /**
+     * Checks if a value is valid.
+     * 
+     * @param {*} value - The value to check.
+     * @returns {boolean} True if the value is valid, otherwise false.
+     */
+    isValidValue(value) {
+        return typeof value === 'number' || value === "variable" || value === "undefined";
+    }
+
+    /**
+     * Updates a property value.
+     * 
+     * @param {string} key - The property key to update.
+     * @param {*} value - The new value for the property.
+     * @throws {Error} If the value is invalid.
+     */
+    updateProperty(key, value) {
+        if (!this.isValidValue(value)) {
+            throw new Error(`Invalid value for property "${key}". Must be a float, "variable", or "undefined".`);
+        }
+        this.values[key] = value;
     }
 
     /**
@@ -22,7 +54,7 @@ export class Properties {
      */
     describe() {
         return Object.entries(this.values)
-            .map(([key, value]) => `${key}: ${value.toString()}`)
+            .map(([key, value]) => `${key}: ${value}`)
             .join(', ');
     }
 }
diff --git a/tests/domain/Element.test.js b/tests/domain/Element.test.js
index 55b7126..2d822e2 100644
--- a/tests/domain/Element.test.js
+++ b/tests/domain/Element.test.js
@@ -56,6 +56,26 @@ describe('Element Class Tests', () => {
         expect(element.properties).to.equal(properties);
     });
 
+    it('Properties should accept a float, a "variable" string, or "undefined"', () => {
+        // Valid cases
+        const validProperties1 = new Properties({ resistance: 100, capacitance: "variable", inductance: "undefined" });
+        expect(validProperties1.values.resistance).to.equal(100);
+        expect(validProperties1.values.capacitance).to.equal("variable");
+        expect(validProperties1.values.inductance).to.equal("undefined");
+    
+        // Invalid cases
+        expect(() => new Properties({ resistance: true })).to.throw(
+            'Invalid value for property "resistance". Must be a float, "variable", or "undefined".'
+        );
+        expect(() => new Properties({ capacitance: null })).to.throw(
+            'Invalid value for property "capacitance". Must be a float, "variable", or "undefined".'
+        );
+        expect(() => new Properties({ inductance: {} })).to.throw(
+            'Invalid value for property "inductance". Must be a float, "variable", or "undefined".'
+        );
+    });
+    
+
     it('An element should throw an error if properties are invalid', () => {
         expect(() => new MockElement('E7', [new Position(10, 20)], null, { invalid: 'properties' })).to.throw(
             "Properties must be an instance of Properties."
diff --git a/tests/domain/ElementService.test.js b/tests/domain/ElementService.test.js
index 2653503..0e5b745 100644
--- a/tests/domain/ElementService.test.js
+++ b/tests/domain/ElementService.test.js
@@ -23,6 +23,10 @@ describe('Element Service Tests', () => {
                 "Terminals must be an array of Position instances."
             );
         });
+
+        it('TO BE CHECKED: All elements should have a label except for wires and junctions', () => {
+            expect(false).to.be.true; // Implement a test for this requirement
+        });
     });
 
     describe('Element Deletion', () => {
@@ -107,4 +111,39 @@ describe('Element Service Tests', () => {
             );
         });
     });
+
+    describe('Element Service Property Updates', () => {
+        it('should update properties through ElementService', () => {
+            const terminals = [new Position(10, 20)];
+            const properties = new Properties({ resistance: 100 });
+            const element = new MockElement('E2', terminals, null, properties);
+    
+            // Update the property to a new float value
+            ElementService.updateProperties(element, { resistance: 200 });
+    
+            expect(element.properties.values.resistance).to.equal(200);
+        });
+
+        it('should allow to define a property as undefined', () => {
+            const terminals = [new Position(10, 20)];
+            const properties = new Properties({ resistance: 100 });
+            const element = new MockElement('E1', terminals, null, properties);
+    
+            // Update the property to undefined
+            ElementService.updateProperties(element, { resistance: "undefined" });
+    
+            expect(element.properties.values.resistance).to.equal("undefined");
+        });
+    
+        it('should allow defining properties as a variable parameter for the simulation engine', () => {
+            const terminals = [new Position(10, 20)];
+            const properties = new Properties({ resistance: 100 });
+            const element = new MockElement('E3', terminals, null, properties);
+    
+            // Define the property as "variable"
+            ElementService.updateProperties(element, { resistance: "variable" });
+    
+            expect(element.properties.values.resistance).to.equal("variable");
+        });
+    });  
 });
\ No newline at end of file