ITEM NAME:125 dB Security System Home Wedge Shaped Door Alarm Stop Stopper System3c System Introduction: This is a stainless steel cover door stop alarm,it is a effective way to deter intruders,the small size of it to save in the travel bags,briefcases, or purses.wonderful for home,office and travel. Product Features 100% brand new and high quality guarantee. Stainless steel cover and small size. Wedge-shaped design alarm stops intruder from opening door. Adjustable sensitivity switch prevents tampering. Features 3 sensitivity levels and extra-loud alarm. 120 dB high-pitched continuous siren when it is activated. Easy to operate, just put it under the door..Features 3 sensitivity levels and extra-loud alarm. Easy to operate, just put it under the door. Powered:1 x 9-volt battery( Not Included).