diff --git a/zip_product_image/README.rst b/zip_product_image/README.rst
index f64a6466..5c3c32e7 100644
--- a/zip_product_image/README.rst
+++ b/zip_product_image/README.rst
@@ -22,7 +22,9 @@ Zip Product Images
 
 |badge1| |badge2| |badge3|
 
-Wizard to generate a zip images of selected products
+Wizard to generate a zip images file of selected variant products.
+
+This module is compatible with fs_product_multi_image module (from OCA/storage) but doesn't depends on it.
 
 **Table of contents**
 
diff --git a/zip_product_image/models/product.py b/zip_product_image/models/product.py
index 84f5326c..9b7e5650 100644
--- a/zip_product_image/models/product.py
+++ b/zip_product_image/models/product.py
@@ -2,6 +2,8 @@
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
 
 import base64
+import imghdr
+
 from odoo import api, models
 
 LIMIT = 500
@@ -29,4 +31,6 @@ def _product_image_data(self):
             if self.image:
                 return (base64.b64encode(self.image.getvalue()), self.image.extension)
             return (False, False)
-        return (self.image_1920 or False, '.jpg')
+        image_data = base64.b64decode(self.image_1920)
+        image_type = imghdr.what(None, h=image_data)
+        return (self.image_1920 or False, f".{image_type}")
diff --git a/zip_product_image/readme/DESCRIPTION.rst b/zip_product_image/readme/DESCRIPTION.rst
index 774b5222..e8618348 100644
--- a/zip_product_image/readme/DESCRIPTION.rst
+++ b/zip_product_image/readme/DESCRIPTION.rst
@@ -1 +1,3 @@
-Wizard to generate a zip images of selected products
+Wizard to generate a zip images file of selected variant products.
+
+This module is compatible with fs_product_multi_image module (from OCA/storage) but doesn't depends on it.
diff --git a/zip_product_image/static/description/index.html b/zip_product_image/static/description/index.html
index 9f1bfff0..717b008e 100644
--- a/zip_product_image/static/description/index.html
+++ b/zip_product_image/static/description/index.html
@@ -369,7 +369,8 @@ <h1 class="title">Zip Product Images</h1>
 !! source digest: sha256:2918847fc8cec3732a3cbdc65ee2f5cb8dfef637c526f6cfd9424bcd6dccd6fc
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
 <p><a class="reference external image-reference" href="https://odoo-community.org/page/development-status"><img alt="Beta" src="https://img.shields.io/badge/maturity-Beta-yellow.png" /></a> <a class="reference external image-reference" href="http://www.gnu.org/licenses/agpl-3.0-standalone.html"><img alt="License: AGPL-3" src="https://img.shields.io/badge/licence-AGPL--3-blue.png" /></a> <a class="reference external image-reference" href="https://github.com/akretion/ak-odoo-incubator/tree/16.0/zip_product_image"><img alt="akretion/ak-odoo-incubator" src="https://img.shields.io/badge/github-akretion%2Fak--odoo--incubator-lightgray.png?logo=github" /></a></p>
-<p>Wizard to generate a zip images of selected products</p>
+<p>Wizard to generate a zip images file of selected variant products.</p>
+<p>This module is compatible with fs_product_multi_image module (from OCA/storage) but doesn’t depends on it.</p>
 <p><strong>Table of contents</strong></p>
 <div class="contents local topic" id="contents">
 <ul class="simple">
diff --git a/zip_product_image/wizards/export_image.py b/zip_product_image/wizards/export_image.py
index 74aa4bc0..6956a108 100644
--- a/zip_product_image/wizards/export_image.py
+++ b/zip_product_image/wizards/export_image.py
@@ -29,9 +29,7 @@ def _get_zip_product_images(self, products):
                     name = ""
                     for field in self._product_field_names():
                         name = name or prd[field]
-                    zip_file.writestr(
-                        f"{name}{extension}", img_data
-                    )
+                    zip_file.writestr(f"{name}.{extension}", img_data)
                 else:
                     logger.warning(f"Product {prd.display_name} has no image")
         if zip_file.filelist: