Just installed this KERUI alarm system in my renovation project after a break-in. For $40, this thing is a STEAL! The 115db siren is legit ear-piercing - I actually had to muffle it with a lid so my neighbors wouldn't hate me during testing.

The setup was simpler than expected, though that 6-second sensor triggering window had me sweating during programming. Pro tip: Keep the manual safe (it's not online!) and watch their slightly awkward English tutorial video if you get stuck.

What surprised me most? The range! I'm using it across my entire worksite with all included sensors (2 motion detectors + 3 door sensors) plus extra remotes. Battery life seems decent so far after 2 months of daily use.

Is it perfect? Nah. The plastic feels cheap-ish, and I wouldn't trust it outdoors in freezing temps. But for basic indoor security when you're away? Absolutely worth every penny. Already planning to buy another for my garage!