Product details:

Highly effective, this wireless alarm alerts you to any unauthorized exits/entries through emergency exit doors and rear doors. Serves as an inexpensive security device and helps deter theft. If the protected door is opened, the electronic Exit Stopper emits an ear piercing alarm for 30 seconds, three minutes or continuously (as preset by the user) and transmits a signal to the included 8-Channel Receiver. A key operated override will silence the alarm and allow authorized exits. The receiver is reset with the push of a button. Another operating option is annunciator mode. Exit Stopper is fitted with a long life 9-VDC alkaline battery. It is available in red or green for almost any type of door, mounting or installation.