This is a great idea and works well WHEN the components of this system work. Unfortunately, the components are cheap Chinese electronic junk that frequently fail. InGRID offers a 1 year warranty as do most companies.
I have had to replace two critical components in the first 18 months and now a third less-than-critical component has failed out of warranty.
Bottom line: Buy carefully. Components are crap and failure tends to occur beyond the warranty period. Alarm system works very well WHEN components function as intended.