This Door Wedge can be easily applied to closed doors, when the door is opened it will activate an alarm alerting you of a possible security breach.<br> Door stop alarm & door stopper keep intruders out, also prevent the doorknob from hitting the wall. <br> High- quality: Made of high damping rubber & abs plastic, very convenient to use. <br> Loud alarm: 120dB loud alarm sound could scare intruder. <br> Portable alert 3 sensitivity levels: Low - Medium - High, with an adjustable sensitivity switch on the side.<br> Easy to Install: Portable and easy way to add piece of mind when traveling or working alone.<br> Widely use: Can be used in home, dorm, office hotel, motel & more. <br> <br> <b>Specification: </b><br> Power by: 9 v battery (not included) <br> Single size: 5.5 * 1.8 * 1.5 inch <br> Single weight: 0.28 lb<br> <br> <b>Package includes: </b><br> 3 x Door stop alarms (9v battery is not included.)