I installed these alarms on every door and window in my house, and wow—they deliver! The moment a door cracks open even slightly, the alarm blares (or chimes, if you prefer). No more worrying about my toddler sneaking out to the backyard pool unnoticed.

The 3-level volume control is a game-changer. On max volume, it’s loud enough to hear from the basement—perfect for deterring intruders. I also love that it doubles as a friendly chime for my home office door.

Installation took seconds: peel, stick, and done. The adhesive is shockingly strong—mine survived a summer thunderstorm stuck to an exterior door. Pro tip: For doors with thick trim (like my front door), I had to angle the sensor creatively, but sliding doors? Flawless.

Battery life surprised me. After 8 months, they’re still going strong. For under $20? These are a no-brainer for rentals, Airbnb hosts, or anyone needing extra security without wiring hassles.