The MSP 420 TW/EN vandal-proof sound projectors, characterised by an aluminium alloy housing and steel front grille, are fitted with fireproof cable according to UNI 9795 2010 (length 80cm). The fixing system makes mounting easy and enables the speaker unit to be turned in the best direction. These speaker units have been developed specifically for use in emergency and evacuation systems and each has its own ceramic terminal strip and thermal fuse. These ensure the protection of the line connecting the loudspeakers if a fire puts one or more of the speaker units connected to it out of use. The MSP 420 TW/EN sound projector has a loudspeaker witha constant voltage transformer (50, 70, 100V) and a swivelling bracket for wall-mounting it.