The University of Oslo is going to acquire a Time-of-Flight Mass Spectrometer (TOF-MS) with the following specifications: compact size (flight tube length < 800 mm, reflectron geometry); bipolar ion detection (+/- switchable); mass resolving power > 5000; quadrupole ion guide interface to a vacuum chamber at 2-50 mbar to be included; analog-to-digital converter (ADC) to be included; PC with preinstalled software and hardware to be included; all vacuum pumps (turbo pump(s), prevacuum pumps; no oil pumps) and pressure gauges to be included; all to be mounted in a portable rack.