Leica's laser tracker can follow a moving retro-reflector, measuring its 3D position 1000 times a second. This single sensor device can achieve accuracies of 10s of microns and has a maximum range of some 35 m. It is increasingly used in manufacturing industry as a flexible and accurate large scale coordinate measuring system, for example to inspect critical locations and surfaces. The paper briefly outlines the operational principles of the tracker's components and highlights the features which make it a practical coordinate measurement system. This makes it an essential tool for re-engineering, improving process capability and increasing tolerance management, all features which reduce process costs and contribute to business improvement. (6 pages)