The GEO-LOK is an inclinometer casing used to house inclinometer probes to measure lateral movements and deformation of soil, rock and structures when installed in near vertical boreholes or settlement, or when installed horizontally in boreholes or trenches. It requires no glue, rivets or shear wires to connect adjacent sections of pipe. Easily disassembled and reused in the event of installation problems, eliminating drill rig stand by time and the cost of replacement casing. Telescopic sections are available.