Smoke Detectors and Fire Alarms Fire Safety, Gentex, Safety & Security, Tools & Home Improvement Gentex GB6-120 Fire Alarm Bell (120VAC/6″) Review by CheatingMutant July 16, 2018 No Comments This fits your . Make sure this fits by entering your model number. Gentex GB6-120 120VAC 6″ Fire Alarm Bell for emergency systems