Limit amount of results returned

How can I limit the amount of results returned?

$images = $wpdb->get_col("
    SELECT ID FROM $wpdb->posts
    WHERE post_type="attachment"
    AND ID in ($meta)
    ORDER BY menu_order ASC
");

$images = $wpdb->get_col("
    SELECT ID FROM $wpdb->posts
    WHERE post_type="attachment"
    AND ID in ($meta)
    ORDER BY menu_order ASC
    LIMIT 5
");

Like @Kaiser suggested you can specify a range (5th to 20th results, a total of 15 results are returned at max) like this:

$images = $wpdb->get_col("
    SELECT ID FROM $wpdb->posts
    WHERE post_type="attachment"
    AND ID in ($meta)
    ORDER BY menu_order ASC
    LIMIT 5,20
");