The PRO-RING concrete-alternative manhole and catch basin grade adjustment system from Cretex Specialty Products is available in round, square and rectangular shapes. They are manufactured from expanded polypropylene, which is known for an exceptional 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 quarter inch of finished grade, and they are watertight. A 6-inch system weighs just 14 pounds and stands up to all kinds of physical abuse. The system can dramatically speed manhole installation and repair time, allowing sites to be opened, repaired and closed in one day, reducing overall costs from 20% to 30% based on conditions. Angle rings are available to match slopes, eliminating the need for mortar and shimming. 800-345-3764 or www.cretexseals.com.