The inclinometer casing model GEO-LOK consists of 1.5 or 3 meters length of ABS pipe with 4 internal grooves spaced 90 degrees apart and running along the entire casing length. Adjoining casing sections are assembled using GEO-LOK’s tightening system: a mating key located within the coupling ensures precise alignment of the casing grooves as succeeding casing lengths are assembled by simply rotating the coupling ring. The casing comes in two diameter sizes: 85 mm and 70 mm OD (3.34”and 2.75”).