The recycled rubber Flex-O-Ring is a type of a Rubber Adjusting Ring and is and ideal choice for many reasons.

Flex-O-Rings are ecological, being constructed of recycled tires.
This rubber material also creates a watertight seal. Flex-O-Rings are resistant to frost, abrasives, and calcium, which reduces repair costs. Flex-O-Rings are available in a variety of thicknesses for a perfect fit, and properly installed, will solve slope or road inclination paving problems.

The Rubber Adjusting Rings (Flex-O-Rings), just like the plastic adjusting rings, are impervious to corrosive effects due to hydrogen sulfide gases and moisture common in sanitary sewers. Additionally, both, the rubber and the plastic adjusting rings are lightweight and easy to install. The Flex-O-Rings and the plastic adjusting rings are readily inspectable which decreases the cost of maintenance. However, the Flex-O-Ring, unlike plastic adjusting ring, provides no voids where moisture can gather, freeze, expand and eventually break the ring.