Ideal Security's Door and Window Contact Alarm detects entry and warns when a door or window has been opened. Perfect for restricted areas where children should not go. It is easy to install using the included double-sided tape. It comes with a 12V (A23(CN23A)) battery and a warning sticker. Ideal Security has been supplying quality hardware to door manufacturers for 65 years. Please explore our other door and window hardware products for your home.