great, thanks that works 🙂
<?php if(get_field("downloads")): ?>
<div id="downloadbox">
<h3>Files</h3>
<ul class="downloads">
<?php while(the_flexible_field("downloads")): ?>
<?php if(get_row_layout() == 'flexible_download'): // layout: Content ?>
<?php $attachment_id = get_sub_field('file');
$url = wp_get_attachment_url( $attachment_id );
$title = get_the_title( $attachment_id );
// part where to get the filesize
$filesize = filesize( get_attached_file( $attachment_id ) );
$filesize = size_format($filesize, 2);
// part where to get the extension
$path_info = pathinfo( get_attached_file( $attachment_id ) );?>
<li class="cf dlbox">
<a href="<?php echo $url; ?>" class="cf">
<span class="dl-title"><?php echo $title; ?><small><nobr><strong>Size:</strong> <em>(<?php echo $filesize; ?>)</em></nobr></small></span>
<span class="dl-extension"><span class="dl-extension-inner"><?php echo $path_info['extension']; ?></span></span>
</a>
</li>
<?php endif; endwhile; ?>
</ul>
</div>
<?php endif; ?>
