Just installed these AKOYU alarms on my patio doors and wow, they're LOUD! The 120dB siren scared my cat (and probably the neighbors) during testing. Perfect for when my toddler tries his Houdini acts with the sliding door.

The peel-and-stick installation took literally 30 seconds per unit. Pro tip: clean the surface with alcohol first - my first attempt failed because of dust. The adhesive feels industrial-grade though, no signs of peeling after two weeks.

Love the multiple modes! Currently using doorbell mode during daytime (less startling for deliveries) and full alarm at night. Battery life seems decent - still going strong after continuous use.

Only gripe? The battery compartment requires ninja fingers to open. Nearly launched the batteries across the room trying to change them. But for under $20? Absolute steal for basic home security peace of mind.