Wireless Home Security Door windows Magnetic Sensor Alarm Entry Alert Chime

Dimension Transmitter:71x48x16mm; receiver:70x104x23mm.
Wireless Receiver is very sensitive, alert when the magnet set(contacts)apart 10mm.
Sound up to 100dbs,48 pcs different tones in for select; operating range(open area):200M
Hight/middle/ low/mute volume adjustable, volume adjustable;Factory 2 year quality warranty.
Easy to install with self-adhesive & screws pack. please make sure the surface is clean and smooth for using self-adhesive otherwise please you can use the screws to install the contact firmly；AC receiver with 2 flat plugs,no need to install.