Alarm Lock PG21MS Narrow Stile Door Alarm Accepts 1-1/8" mortise cylinder inside, rim cylinder outside, long tailpiece recommended 9V battery included with low alert & flashing LED - 9-1/2" W x 2" H x 2-3/8" Has programmable 15 sec. entry or delay, comes with two types of tamper proof switches Audible low battery warning, 3 Programmable 95 db siren styles: sweep, pulsed and steady Dimensions: 9" W x 2-1/2" H x 2-3/8" D, For exterior key control, optional rim cylinder may be used