Too many young lives are needlessly put at risk or lost due to accidental septic tank entry. This safety screen is an inexpensive but effective solution to prevent this from happening. The Polylok 600mm (20″) Safety Screen acts as a secondary layer of protection if a riser cover is unknowingly damaged, dislodged or removed. This safety screen fits the Polylok 600 x 150mm (24″) diameter riser. It fits in the uppermost riser and prevents accidental entry into the septic tank by children, household pets or wild animals. It installs in seconds and can be screwed into place for extra security.