InfoComm 2017: SureCall Talks About Guardian3 QR Public Safety Communications Signal AmplifierJune 16, 2017 | Home / June 16, 2017 rave-video / InfoComm 2017: SureCall Talks About Guardian3 QR Public Safety Communications Signal Amplifier Look in: Infocomm 17 InfoComm 2017: SureCall Talks About Guardian3 QR Public Safety Communications Signal Amplifier