The flash premiums of VADs are concerning 0.five Hz and a couple of Hz. VADs may well involve a synchronisation functionality to reduce the opportunity of a flash frequency that could bring about adverse consequences, for instance inducing epileptic suits, when units are in near proximity. Installation in Large-Noise Places: https://www.firesense.co.uk/type/conventional-fire-system/conventional-sounders-vids-vads/