Just installed these Sanjie door alarms and wow, they are LOUD. Like, 'my-neighbors-probably-think-there's-a-burglar' loud. Perfect for keeping my toddler from sneaking out or alerting me if someone tries to open a window.

The installation was super easy—just peel and stick with the 3M tape. The adhesive is strong, almost too strong. Had to pry one off to adjust it, and let’s just say the door won that battle.

Love the volume control options: 125dB for maximum scare, 100dB for a slightly less ear-shattering experience, or a chime mode if you just want a gentle ding. But let’s be real, I’m here for the panic-inducing siren.

Battery life seems solid (comes with LR44 batteries), and the low-battery alert is a nice touch. No complaints there.

One gripe: the on/off switch is tiny and hard to see. Had to use a flashlight to figure it out. Might paint it neon or something.

Overall, these are a cheap, effective way to boost home security. Just... maybe warn your housemates before testing.