<?xml version="1.0"?>
<list string="Product Variants" editable="bottom">
                    <field name="name" readonly="1"/>
                    <field name="default_code" readonly="1" optional="show"/>
                    <field name="product_template_variant_value_ids" widget="many2many_tags" groups="product.group_product_variant" readonly="1"/>
                    <field name="description" readonly="1" optional="show"/>
                </list>
            