Greencycle 10PK Door & Window Alarm — 110dB, 4-Mode Magnetic Sensor (Continuous 10s Alarm, Doorbell, Door-Left-Open Reminder/Delay) — Adhesive Mount for Fridge, Sliding Door, Dormitory, Home, Shop

Compact, adhesive-mounted security sensors from Greencycle — sold in a 10PK — that warn when doors or windows open and provide multiple alert options. The unit combines four core functions: alarm, continuous alarm, doorbell, and a door-closing/left-open reminder, making it useful for protection, notifications, and everyday convenience. Modes and behavior: three adjustable operating modes let you tailor alerts — continuous alarm mode (sounds for 10 seconds when a door or window opens), door closing/left-open reminder mode (emits three quick prompt tones when the door moves from closed to open), and doorbell mode (a single prompt tone on opening). A door alarm delay/left-open reminder feature is included to help avoid false alarms while notifying you when a door remains open. Loudness and battery: the built-in alarm reaches 110dB, providing a powerful deterrent and ensuring the alert is heard even in quiet settings. The device also has a low-battery warning that emits an audible alert when battery replacement or recharging is needed, helping maintain continuous protection. Installation and use: no wiring or tools required — each sensor attaches with the supplied double-sided adhesive tape for quick placement on doors, windows, sliding doors, refrigerators, freezers, filing cabinets and similar surfaces. Ideal for dormitories, homes, shops and other indoor spaces where easy, reliable notification is needed.