1 Vibration test systems, equipment and components thereof, other than those specified in Dual-Use code 2B116— a vibration test systems employing feedback or closed loop techniques and incorporating a digital controller, capable of vibrating a system at an acceleration equal to or greater than 0,1 g rms between 0,1 Hz and 2 kHz and imparting forces equal to or greater than 50 kN, measured “bare table”; b digital controllers, combined with specially designed vibration test software, with a real-time control bandwidth greater than 5 kHz designed for use with vibration test systems specified in paragraph (a); c vibration thrusters (shaker units), with or without associated amplifiers, capable of imparting a force equal to or greater than 50 kN, measured “bare table”, and usable in vibration test systems specified in paragraph (a); d rest piece support structures and electronic units designed to combine multiple shaker units in a system capable of providing an effective combined force equal to or greater than 50 kN, measured “bare table”, and usable in vibration systems specified in paragraph (a). 2 In this paragraph— “ bare table ” means a flat table, or surface, with no fixture or fittings. “ real-time control bandwidth ” means the maximum rate at which a controller can execute complete cycles of sampling, processing data and transmitting control signals.