diff --git a/assets/html/en/index.html b/assets/html/en/index.html
index c4aa6b33..e0bb42e2 100644
--- a/assets/html/en/index.html
+++ b/assets/html/en/index.html
@@ -50,7 +50,7 @@
         <td style="border:none;">
             <table>
                 <tr>
-                    <td style="border:none;padding:0;padding:0"><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=3RTGWJRNAW2PU"><img src="../img/paypal.gif" alt=""/></a> </td>
+                    <td style="border:none;padding:0;padding:0"><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=3RTGWJRNAW2PU"><img src="../img/paypal.png" alt=""/></a> </td>
                 </tr>
                 <tr>
                     <td style="text-align:center;border:none;padding:0">&euro;10</td>
@@ -60,7 +60,7 @@
         <td style="border:none;">
             <table>
                 <tr>
-                    <td style="border:none;padding:0"><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=UCUUB2TYE4PGN"><img src="../img/paypal.gif" alt=""/></a> </td>
+                    <td style="border:none;padding:0"><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=UCUUB2TYE4PGN"><img src="../img/paypal.png" alt=""/></a> </td>
                 </tr>
                 <tr>
                     <td style="text-align:center;border:none;padding:0">&euro;20</td>
@@ -70,7 +70,7 @@
         <td style="border:none;">
             <table>
                 <tr>
-                    <td style="border:none;padding:0"><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=3M6TFHWEPSU44"><img src="../img/paypal.gif" alt=""/></a> </td>
+                    <td style="border:none;padding:0"><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=3M6TFHWEPSU44"><img src="../img/paypal.png" alt=""/></a> </td>
                 </tr>
                 <tr>
                     <td style="text-align:center;border:none;padding:0">&euro;25</td>
@@ -80,7 +80,7 @@
         <td style="border:none;">
             <table>
                 <tr>
-                    <td style="border:none;padding:0"><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=5KP7LPQU77UAS"><img src="../img/paypal.gif" alt=""/></a> </td>
+                    <td style="border:none;padding:0"><a href="https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=5KP7LPQU77UAS"><img src="../img/paypal.png" alt=""/></a> </td>
                 </tr>
                 <tr>
                     <td style="text-align:center;border:none;padding:0">&euro;30</td>
diff --git a/assets/html/img/paypal.gif b/assets/html/img/paypal.gif
deleted file mode 100644
index d017250a..00000000
Binary files a/assets/html/img/paypal.gif and /dev/null differ
diff --git a/assets/html/img/paypal.png b/assets/html/img/paypal.png
new file mode 100644
index 00000000..65632937
Binary files /dev/null and b/assets/html/img/paypal.png differ
diff --git a/assets/html/img/ultrasonic.png b/assets/html/img/ultrasonic.png
index 5a4fb287..8b8ef219 100644
Binary files a/assets/html/img/ultrasonic.png and b/assets/html/img/ultrasonic.png differ