The 48" center mounted chassis dynamometers are the most common type and are typically used for emission testing and mileage accumulation. They are equipped with rollers and a motor, which is positioned between the rollers. Inline versions with the motor located inline with the rollers are mainly used for NVH testing. The basic chassis dynamometer facility includes roller set, power and control cabinets, an operating PC, a handheld remote unit, a blower, and safety covers and grids. In addition, the mileage accumulation extension consists of an automation system, an autopilot and interface unit for connections between automation system to the autopilot as well as to some required vehicle signals, like engine speed, temperature signals or ignition. The HORIBA 48" chassis dynamometer is capable of achieving averaged accumulated distances of up to 500,000 km per year.