Ideally used in sewer and drainage manholes or pits. For fitting into new and existing concrete structures. They can be set into pre-cast structures during concrete pour, caulked into a drilled hole with epoxy resin or fixed with quick setting cement.
They are manufactured using virgin polypropylene copolymer plastic and reinforced with structural carbon steel.
Polypropylene is used in the manufacture of car battery cases, which shows how resistant it is to concentrated sulphuric acid.