Intruder alert... It's the Super-Loud Magnetic Door Sensor Alarm Super loud 120 decibel alarm is sure to wake you up to let you know about visitors Easily peel and stick onto your door frame with the included adhesive Motion sensor switch can be turned on and off when you choose Ideal for entrances to your home, office, hotel room, garage and more Dimensions: 2.8" x 1.3" x 0.5" Materials: plastic Choose from a pack of 2 or 4 Buying Options: 14.99 pounds instead of 49.99 pounds for the 2-Pack - save 70% 26.99 pounds instead of 94.99 pounds for the 4-Pack - save 72%