RoGer YL-9805 Door and Window Sensor

Wireless alarm that can be mounted on doors and windows. Due to its small dimensions, it is hardly visible, so it does not take up window or door space. The device does not require any assembly that interferes with the structure of the door or window frame, just stick both devices. The alarm volume reaches 90 dB, so it can scare away potential intruders. The device is very energy-efficient, powered by three 1.5 V LR 44 batteries, which will need to be replaced no more than once a year.