Profile: American Highway Products Ltd. manufactures manhole risers, catch basin risers and water/gas valve risers. Our sewer lid seal products reduce moisture penetration and eliminate lid vibration. We fabricate monument box risers, water and gas valve box risers & rubber adjustment rings. We also deliver steel manhole risers, catch basin risers, monument box risers, rubber adjustment rings and sewer lid seal products. Our manhole riser rings render a flat surface for seating manhole covers.