Hamilton Kent, established in 1943, is a leading international manufacturer of rubber gaskets for pipe and manhole joints in the water and wastewater industries. HK produces a broad line of flexible rubber pipe-to-structure connectors to ensure watertightness at these locations. Hamilton Kent offers The Lifespan System¬: a corrosion-proof, lightweight, watertight, rubber manhole frame, supplied with cast iron or composite lock-down covers, designed to eliminate rain-derived inflow through the top of the manhole. Lifespan also prevents cover theft and unauthorized access, eliminates rattling covers and requirement of heavy installation equipment. It performs equally well in off-road and heavy traffic areas. The system comes in 24î, 27î or 30î clear opening sizes, with tapered rubber adjustment risers that simplify matching the top of the frame with the slope of the surface.