$URL = "#";
$attachment_args = array(
'post_type' => 'attachment',
'post_mime_type' => 'application/zip',
'post_status' => "inherit", // attachments don't have statuses
'post_parent' => $post->ID
);
// get the posts
$this_posts_attachments = get_posts( $attachment_args );
//var_dump($this_posts_attachments);
//var_dump( $product );
if ( count($this_posts_attachments) > 0 ) {
$URL = $this_posts_attachments[0]->guid;
}