Pack of 5 DEPS has been manufacturing 50mm Cascreen Environmental casing and screen for over 20years, it was manufactured for the safe testing of ground sites in the chemical, roadways,Manufactures and Petro sites. They are made from 50mm or 2" UPVC this only has virgin material and meets all the AS codes of manufacturing, The threads and o-ring seal have been designed for ease of assembly, sealing in the threaded joints and thread strength for maximum depth installation possibilities. With only using virgin materials there is no chance of the test results being effected by leaching form the cascreen monitoring well materials.