PRO-RING from Cretex Specialty Products is an advanced concrete-alternative manhole and catch basin grade adjustment system. Available in round, square and rectangular models, these rings are manufactured from expanded polypropylene, which is renowned for its strength-to-weight ratio, durability, chemical resistance and long service life under harsh conditions. One man can install the system in just minutes to within a 1/4 inch of finished grade, and they are watertight. Where concrete rings break and may cause injury, the system eliminates that hazard, helping minimize the risk of injury. A 6-inch unit weighs 14 pounds and stands up to physical abuse, speeding manhole installation and repair time. Manhole repair sites can be opened, repaired and closed in one day, reducing overall costs. Angle rings are available to match slopes, eliminating the need for mortar and shimming. 800/345-3764; www.cretexseals.com.