... sensitivity: less than -100.Product Name: Wireless Voice/Non-visual Doorbell 1,2.4G ISM Public Frequency Band:2402MHz-2479MHz2,Transfer ... red light and ring when receive the signal, Will beep 'ding-dong' stop ringing ,about 1 minute, then entering standby.If off ... not ring, the loud sound 'ding-dong', Outdoor monitorweight 15 beeps, re-timed one minute. wireless voice doorbell with clear voice for hot ...