A surge protector designed to protect any RS-232 port from the possibility of low level induced mains voltage transients. The ABS-bodied surge protector uses metal oxide varistors (MOV’s) to protect pins 2, 3, and 7.,It has one male and one female connector with all 25 pins connected straight through. MOV’s are connected between pins 1 and 2, 1 and 3, and 1 and 7. The MOV’s will suppress any voltage above 30 volts without affecting the normal RS-232 operation. The MOV’s are capable of suppressing one joule of energy and 250 A peak current.