Doberman Security SE-0129-4PK Mini Entry Defender with Chime - 4 Pack (Black) MAGNETIC TRIGGER TECHNOLOGY - Loud 100 dB alarm alerts you of potential break-ins and when someone enters the house/room or front door of an office. STURDY, COMPACT DESIGN - Detects entry and fits on any door or window - perfect for home, office, dorm room or even RVs EASY INSTALLATION - Simply peel and stick, no tools needed. PERFECT FOR YOUNG & OLD - Safely prevent young children or wandering elderly from leaving the house Superior adhesive backing for optimum sticking power