Septic tank Universal Safety Screens from Polylok work with the company’s 12-, 20- and 24-inch risers. The 24-inch unit works with PVC ribbed pipe, HDPE corrugated pipe and concrete risers. The Lid-Lok safety device works with the company’s 20- and 24-inch riser covers. When used with the 20-inch Dual Safety Cover for a 24-inch riser pan, the secondary safety devices can help prevent accidents. 877-765-9565; www.polylok.com.