The Leica Absolute Tracker AT901 is a portable measurement system that can be used for the inspection of spherical volumes of up to 160 m as it is equipped with Absolute Interferometer and PowerLock systems. The AT901 series features three models designed for different inspection types: Basic, Mid Range and Long Range. The Basic model uses a reflector and features a range of up to 160 m and represents an excellent solution for the positioning of machines, fixtures or jigs as well as alignment of tools, roll mills, presses or gantry based machines. The Mid Range version can be used when direct line of sight is unavailable while the Large Range model is capable of full wireless probing.