The TESTO 512 is an excellent measuring system, perfect for substituting multiple devices needed for a technician's work. The TopSafe design protects the device from damage, dirt or water. The 512 has 2 switchable flow units: m/s and fpm. Also, it contains eight pressure units: kPa, hPa, Pa, mmH2O, mmHg, psi, inch H2O, inch Hg, providing a wide range of usability, without the need to manually convert the units. Also, it contains a HOLD button, so as to keep the value on display. It has an internal memory that stores the maximum and minimum values of measurements. It also features an adjustable damping for sliding mean calculation, as well as a built-in density compensation.