[3 sensitivity grade] There is an adjustable sensitivity switch on the side to control the high-medium-low sensitivity level of the door alarm[Loud alarm] 120-decibel high-pitched alarm remind the owner and scare off intruders[Non-slip bottom] non-slip rubber pad is used on the bottom to prevent thieves from entering without an alarm[Easy to install] no wiring required; battery-powered (1x9V battery required, not included); just put it under any door[Function] You can use it as a common door stopper when turn down the ON/OFF switch, hold the the open position.Volume: equal 120(dB)Working voltage:9(V)Working current:0.2(mA)Three sensitivity:High, Medium, LowShape:Wedge-shaped[Applicable scene] perfect for bedrooms, hotels, apartments, dorm rooms, front doors, etc; peace of mind when traveling or working alonePower Suplly:1 x 9V battery(Not included batteries)Colour:As ShownMaterial:Stainless steel+PlasticSize:14x4.5x4cmPackage Contents:2 x Door Stopper Security AlarmOnly 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.