6 Packs x Window Door Security Alarm Low Price and High Quality Security System ，Magnetic sensor switch detects entry 1. Super loud 90 dB alarm 2. Warning door / window sticker is supplied free in package 3. Easily mounted by adhesive. Type to window or door. Ideal entry warning for homes， apartments， mobile homes， do rms， offices， hotel rooms， garages， and more! 4. Super environmental suitability and stability 5. Dustproof and insect prevention 6. Convenience in installation--just peel and stick 7. Magnetic sensor switch detects entry protecting your home or office whether you are in or out 8. Operated by 3pcs of. 5VLR44 / AG 13 button cell ( included ) Specifications: 1.Sensor type: alarm 2.Alarm type: sound 3.Material: plastic 4.Color: White 5.Size: 6.2cm x 3.2cm x 2cm What's in the Pack? 6 x Magnetic Sensor 6 x Magnetic Stick 18 x LR44 Button Battery ( in the sensor )