[REUSABLE]: Trip wire perimeter alarms can be reused indefinitely and can be deployed on any path, entry area, connected to doors, gates, etc. [EARLY WARNING SYSTEM]: Enhance perimeter security on private property, campgrounds, farms, barns, or restricted areas, and alert for perimeter intrusions. [SIMPLE AND RELIABLE]: Trip line alarm is easy to set up, simple and effective, yet reliable, and are a cost effective solution to alert you to intruders. [HOW IT WORKS]: Multiple trip wires are used on a single device to provide a trip alarm with 360 degree whole coverage. When the alarm is activated, it emit a loud audible alarm. NOTE: Our device not harm anything, itand#39;s just designed to make a loud sound to remind you to keep safe,Any question please let me know, we reply with a proper solution within 24 hour. [APPLICATIONS]: Olive green color, ideal for wooded areas, can be used in buildings, yards, courtyards and building exteriors, easily attached to trees, posts or frames by screw holes or zipper cuts. Specification:Item Type: Perimeter Trip Alarm Weight: . 148g/5.2oz Product Size: . 3.2x2.4x9.5cm/1.3x0.9x3.7inch Colour:black Material:Metal Package Contents: 6 * Perimeter Alarm Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.