MAGNETIC: The alarms work thanks to the magnetism between the alarm transmitter and the magnet receiver. The 100 dB siren is triggered when an equipped door or window is opened (trigger spacing: more than 10 mm). EASY: The alarm sensor and the magnetic receiver are equipped with a adhesive tape. No need for tools, just stick them on a door frame. TECHNICAL DETAILS: Transmitter dimensions: 9 x 3 x 2 cm; magnet receiver: 5 x 1 x 1.5 cm | Batteries: 2x AAA 1.5V per alarm (Does not contain)| Volume: 90dB NUMEROUS USES: Increase the security of your front door, terrace or balcony, your bedroom or that of the children - the set of 4 alarms and receivers give you the choice. p> NOTE: Please ensure that your apartment or house has the right conditions for the installation of the security system, without accidental triggering. EVERYWHERE AT YOUR HOME Secure your home in different places thanks to the set of 4 alarms: front door, balcony, garden, bedrooms, windows. EASY Installing the alarm requires no tools or cables. Simply stick it to a window sill or door frame using the adhesive strips included with each part. Magnetic operation takes care of the rest. DISCREET Small alarms are practical and discreet. Their white design does not degrade the aesthetics of your room. NOTE Make sure that your apartment or house has the right conditions for the installation of the security system, without accidental triggering (the transmitter - receiver distance must not exceed 10mm). TECHNICAL DATA Transmitter dimensions: 9 x 3 x 2 cm / receiver: 5 x 1 x 1, 5 cm Batteries: 2x AAA 1.5V per alarm (Does not contain) Volume: 90dB Maximum distance between transmitter and receiver: 10 mm