<td style="width: auto;"><?php
                $product = new WC_Product(get_the_ID()); ?>
                <a href="<?php the_permalink() ?>" target="_blank">
                <?php echo $product->get_attribute('pa_voedings-spanning-dc-ac'); ?>
                <text>-</text>
                <?php echo $product->get_attribute('pa_voedings-spanning-dcac'); ?>
                </a>
            </td>