Features: Magnetic Sensor Design: Magnetic sensor with high sensitivity, when the doors and windows are opened, the burglar alarm will remind you that someone has entered your house without permission. Loud Alarm: Super loud up to 80dB or more. When someone opens the door or window illegally (the relative position of the primary and secondary parts changes), the alarm can issue a strong alarm, warning the intruder to leave and remind the owner Easy Installation: Magnetic sensor switch detects your door or window.Easy stick installation and operation, press on/off switch to power on/off(3pcs button cell battery is included in the main body),tear the double-sided adhesive on the backpack,paste the door knob alarm on your target position. Wide Applications: The alarm is suitable for doors, window and lockers to guard against theft. Ideal entry warning for homes,apartments,mobile homes,offices,hotel rooms,garages,and more Package Included: Our package come with 6pcs door alarm main body and 6pcs magnetic stripe. Enough quantity for your home use.Security systems can make your life more enjoyable. Specification Material: Plastic, magnet, core Color: White Main Body size(L x W x H): About 6 x 3 x 2cm/2.36 x 1.18 x 0.79inch Magnetic strip size(L x W x H): About 5.4 x 1.3 x 1.1cm/2.13 x 0.51 x 0.43inch Siren loudness: 90 decibels Power supply: 3pcs 1.5V button cell battery (included) Method of use 1.Ensure that the switch is placed in the OFF position, according to the correct direction into the three button batteries, and install the battery door 2. The main machine and magnetic box according to the direction fixed on the cabinet, window, etc. The arrow on the magnetic box points to the host, and the magnetic box should be on the side of the host with a buckle. And the magnetic box and the host should be within the magnetic control distance. 3. Set the switch to ON and the buzzer will start to sound: when the door and window are closed, the buzzer will stop sounding and the machine will be ON alert Package included: 6pcs x Main Body 6pcs x Magnetic Stripe Note: Due to the light and screen difference, the items color may be slightly different from the pictures. Please allow 0.5-2cm differences due to manual measurement.