4-in-1 Multi-Function Alarm: General Alarm, Constant Alarm, Closing-Door Alert (Time Delay), and Doorbell Powered by 2 AAA batteries (batteries not included) Self-adhesive design for easy installation and operation 108 dB loud alarm for enhanced security General Alarm Mode: Sounds when doors or windows are opened; stops when closed Constant Alarm Mode: Sounds continuously once triggered Time Delay Mode: Emits a “beep-beep-beep” sound 15 seconds after doors or windows are opened (adjustable delay options: 3/15/30/60 seconds; factory default is 15 seconds) — ideal for use with freezers or refrigerators Material: ABS Color: White Package Includes: 4 x Door/Window Alarms, 4 x Magnetic Strips, Double-Sided Adhesive Stickers, User Manual Note: Color appearance may vary slightly due to lighting and screen settings. Measurement tolerance: ±1–3 cm.