Sonic Alarm System Kit - Window Doors and Cabinet with Alarm and Chime Modes 4-pack with Magnetic Sensor - All in One System - Includes 4 Alarms. Batteries Included. Brand: Perfect Life Ideas Wireless Audible Door And Window Alarm System Alerts You if An Intruder Enters Your Home. Package includes 4 Alarm Modules And Magnetic Sensors. Batteries Included. Piercing Alarm Deters Intruders - Also Has Chime Setting. Great For Monitoring Door Activity With Kids Self Adhesive Backing. No Tools Needed/Installs In Minutes.