The bailey 1986 drain testing u air gauge is a precision measuring instrument designed for testing drains and sewers to building regulations standards. This professional grade u gauge provides accurate pressure readings during drain testing procedures, making it an essential tool for plumbers, drainage engineers and building contractors working on new installations or maintenance projects. The 100mm 4in u gauge design allows clear visibility of air pressure levels during testing, helping ensure drainage systems meet the required standards before sign off. This air testing gauge is suitable for use with drain testing equipment to verify the integrity of pipework and identify potential leaks in domestic and commercial drainage installations. Ideal for compliance testing on new build projects, renovation work and routine drainage system inspections, this u gauge delivers reliable performance in professional drainage applications. Specifications tool type u gauge size 100mm 4in.