CallToU Business Door Entry Chime Door Open Alert for Store Home Office Door Alarm with Chime Adjustable Volume 55 Ringtones (Black) medical alert aystem after a sudden power failure

after a sudden power failure to re-power

The 2000mAh battery supports all-day use

and a speaker in one compact device

This door and window sensor alarm security kit come with self adhesive pads so no tools are required

the Group Function lets you call all stations in the intercom system at once

CallToU Business Door Entry Chime Door Open Alert for Store Home Office Door Alarm with Chime Adjustable Volume 55 Ringtones (Black) medical alert aystem after a sudden power failureEasy to InstallThe sensor and receiver are paired already,Just plug the receiver into standard outlet, tear the double side adhesive tape of the door window sensor and stick them to any door or window. Long Range & ExpandableThe door chime wireless door sensor has 1000feets far enough to cover every door in your house or store. And each door opening chime for business can be paired unlimited magnetic sensor, you can also pair different ringtone to