On Spree 4.2 it's correct hidden_field_tag in slides form to get products? <div class="col-md-12"> <%= f.field_container :product_id do %> <%= label_tag :product_id, t(:product) %><br> <%= hidden_field_tag 'slide[product_id]', f.object.product_id.to_s, class: "product_picker fullwidth" %> <% end %> </div>