Attachment file display link text

I’ve changed the button to:

    <a class="button big brand-1" a href="https://wordpress.stackexchange.com/questions/221483/<?php echo wp_get_attachment_url($attachment->ID, false); ?>">
            <?php echo $default_strings['price_text'][ $lang ]; ?>
    </a>

a href is added around the wp_get_attachment_url rather than using the_attachment_link which contains the whole link.