Polylok Inc. / Zabel offers 20-inch risers in 2- and 3-inch heights. These risers are similar to the company’s 24-by-3-inch riser pan. Whether working with a septic tank, distribution box or drainage box, stacking these heights with the company’s existing series of 6- and 12-inch risers enables installers to get the required fit. A concrete plug can be installed in the 20- and 24-inch riser series, and safety screens are available to provide a secondary layer of protection. 877/765-9565; www.polylok.com.