diff --git a/assets/js/sccp_manager.js b/assets/js/sccp_manager.js
index ef3ccb7..6c3b326 100644
--- a/assets/js/sccp_manager.js
+++ b/assets/js/sccp_manager.js
@@ -281,7 +281,8 @@ $(document).ready(function () {
     });
 // Form.adddevice
     $('.hw_select').change(function (e) {
-//        console.log('HwSelect');
+        // data-val contains the number of buttons for this type
+        // data-id contains the max number of addons (1 = 0, 3 = 2)
         var type_id = $('#sccp_hw_type').find(':selected').data('id');
         var btn_dev = $('#sccp_hw_type').find(':selected').data('val');
         if (type_id === 1) {
@@ -290,17 +291,26 @@ $(document).ready(function () {
             }
             $('#sccp_hw_addon').attr("disabled", "disabled");
         } else {
-            $('#sccp_hw_addon').removeAttr('disabled');
+            $('#sccp_hw_addon').prop('disabled',false);
+        }
+        // when edit, btn_dev is undefined as no select, so send btn_dev with page
+        if (btn_dev == null) {
+            var btn_dev = $('#devButtonCnt').val();
         }
-
         var btn_add = $('#sccp_hw_addon').find(':selected').data('val');
-        $('#buttonscount').attr('value',btn_dev + btn_add);
+        // btn_add is empty if none selected
+        if ((btn_add == null) || (btn_add == '')) {
+            var btn_add = 0;
+        }
+        var totButtons = parseInt(btn_dev, 10) + parseInt(btn_add, 10);
+        $('#buttonscount').attr('value', totButtons);
         $('.line_button').each(function () {
-            if ($(this).data('id') < btn_dev + btn_add) {
+            if ($(this).data('id') < totButtons) {
                 $(this).removeClass('hidden');
-                $(this).removeAttr('hidden')
+                $(this).removeAttr('hidden');
             } else {
                 $(this).addClass('hidden');
+                $(this).attr('hidden', true);
             }
         });
     });
diff --git a/conf/sccpgeneral.xml.v433 b/conf/sccpgeneral.xml.v433
index 3a1d5c9..48e3d92 100644
--- a/conf/sccpgeneral.xml.v433
+++ b/conf/sccpgeneral.xml.v433
@@ -1298,13 +1298,12 @@ and open the template in the editor. Base Version before all crash :-)
             </input>
             <help>The type of phone: 7911, 7940, 7960, etc. Important note: the 'G' models are handled as the base model (e.g., 7962G is handled as 7962). In the Display mode, this field is read-only because the MAC address and the model number are a pair.</help>
         </item>
-        <item type="IE" id="3" seq="99">
+        <item type="SDE" id="3" seq="99">
             <label>Addon</label>
-            <input>
-                <name>addon</name>
-                <default>NONE</default>
-                <class>sccp-custom</class>
-            </input>
+            <name>addon</name>
+            <default>NONE</default>
+            <select name="model" dataval="buttons">description</select>
+            <class>hw_select form-control</class>
             <help>Addon: Addons are model specific and only work with certain base phones. This phone model is identified as being a phone that does not accept sidecars. Update devmodel if this is not correct.</help>
         </item>
     </page_group>
diff --git a/sccpManClasses/formcreate.class.php b/sccpManClasses/formcreate.class.php
index e1ac17e..184805a 100644
--- a/sccpManClasses/formcreate.class.php
+++ b/sccpManClasses/formcreate.class.php
@@ -759,7 +759,7 @@ class formcreate
                 break;
             case 'SDE':
                 $extension_list = \FreePBX::Sccp_manager()->dbinterface->getDb_model_info('extension', 'model');
-                $extension_list[]=array( 'model' => 'NONE', 'vendor' => 'CISCO', 'dns' => '0');
+                $extension_list[] = array( 'model' => 'NONE', 'vendor' => 'CISCO', 'dns' => '0');
                 foreach ($extension_list as &$data) {
                     $d_name = explode(';', $data['model']);
                     if (is_array($d_name) && (count($d_name) > 1)) {
diff --git a/views/form.buttons.php b/views/form.buttons.php
index 15fc7a4..48e224a 100644
--- a/views/form.buttons.php
+++ b/views/form.buttons.php
@@ -31,30 +31,30 @@ $hint_list  = $this->getHintInformation(true, array('context'=>'park-hints')) ;
 
 // print_r($hint_list);
 $line_id =0;
-$max_buttons =56;     //Don't know hardware type so et a maximum. On save, this is set to actual max buttons
+$max_buttons =56;     //Don't know hardware type so set a maximum. On save, this is set to actual max buttons
 $show_buttons =1;
 //print_r($hint_list);
 if (!empty($_REQUEST['id'])) {
     $dev_id = $_REQUEST['id'];
     $db_buttons = $this->dbinterface->getSccpDeviceTableData('get_sccpdevice_buttons', array("id" => $dev_id));
     $db_device = $this->dbinterface->getSccpDeviceTableData('get_sccpdevice_byid', array("id" => $dev_id));
-    $max_buttons = $db_device['buttons'];
+    $show_buttons = $db_device['buttons'];
     if (!empty($db_device['addon_buttons'])) {
-        $max_buttons += $db_device['addon_buttons'];
+        $show_buttons += $db_device['addon_buttons'];
     }
-    $show_buttons = $max_buttons;
+    //$show_buttons = $max_buttons;
 }
 if (!empty($_REQUEST['new_id'])) {
     $val = $_REQUEST['type'];
     $dev_schema =  $this-> getSccpModelInformation('byid', false, "all", array('model' =>$val));
 //   $db_device = $this->dbinterface->getSccpDeviceTableData('get_sccpdevice_byid', array("id" => $val));
-    $max_buttons = $dev_schema[0]['buttons'];
+    $show_buttons = $dev_schema[0]['buttons'];
     if (!empty($_REQUEST['addon'])) {
         $val = $_REQUEST['addon'];
         $dev_schema =  $this-> getSccpModelInformation('byid', false, "all", array('model' =>$val));
-        $max_buttons += $dev_schema[0]['buttons'];
+        $show_buttons += $dev_schema[0]['buttons'];
     }
-    $show_buttons = $max_buttons;
+    //$show_buttons = $max_buttons;
 }
 if (!empty($_REQUEST['ru_id'])) {
     $dev_id = $_REQUEST['ru_id'];
@@ -67,7 +67,8 @@ if (!empty($_REQUEST['ru_id'])) {
 <form autocomplete="off" name="frm_editbuttons" id="frm_editbuttons" class="fpbx-submit" action="" method="post" data-id="hw_edit">
     <input type="hidden" name="category" value="frm_editbuttons">
     <input type="hidden" name="Submit" value="Submit">
-    <input type="hidden" name="buttonscount" id="buttonscount" value="<?php echo $max_buttons?>">
+    <input type="hidden" name="buttonscount" id="buttonscount" value="<?php echo $show_buttons;?>">
+    <input type="hidden" name="devButtonCnt" id="devButtonCnt" value="<?php echo (!empty($db_device['buttons']))?$db_device['buttons']:0;?>">
     <div class="section-title" data-for="<?php echo $forminfo[0]['name'];?>">
         <h3><i class="fa fa-minus"></i><?php echo _($forminfo[0]['label']) ?></h3>
     </div>