The Polylok 600mm (24″) Universal Safety Screen acts as a secondary layer of protection if the riser cover was unknowingly damaged or removed. This safety screen is designed to be installed in any 600 internal diameter riser or extension shaft whether concrete plastic or fibre glass. It is supplied with a retainer ring which is fixed to the riser extension shaft and supports the safety screen when fitted. Prevent accidental tank/pipe entry (by children and pets or wild animals) by installing this inexpensive protection, it installs in seconds.