This door alarm is easy to install; simply attach the alarm sensor to your window or door, and you're done. It can also be used as a door stop alarm, pool door alarm, garage door alarm, or sliding door alarm system. Magnetic trigger: When children, the elderly, and dementia patients open doors or indoor doors, the alarm sounds, preventing accidents and keeping toddlers and seniors away from cabinets, pools, monitoring wandering, sleepwalking, etc. This door alarm instantly detects any door movement, stopping intruders with our powerful alarm system. The anti-theft design may be slightly loud for children, so remember not to scare them. Color: White Material: Plastic Package Contents: 1 * Smart Door and Window Alarm Sensor Only the above package content is included; other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to differ slightly from the real thing. The allowed measurement error is +/- 1-3 cm.