PRO-RING™ is the most advanced concrete-alternative manhole and catch basin grade adjustment system available anywhere. Available in round, square and rectangular, these rings are manufactured from Expanded Polypropylene (EPP) which is renowned for its exceptional strength to weight ratio, durability, chemical resistance and long service life under harsh conditions. One man can install the PRO-RING™ system in just minutes to within a quarter inch of finished grade and they are watertight. Where concrete rings break and may cause injury, the PRO-RING™ system eliminates the hazard, helping minimize the risk of injury. A 6” PRO-RING™ weighs just 14 pounds and stands up to all kinds of physical abuse. The PRO-RING™ system dramatically speeds manhole installation and repair time. Manhole repair sites can 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, which eliminates the need for mortar and shimming.