"Portable" Security Systems?

[Travis Beehler]

Hey all!  When you have a rental that is empty, one of the biggest fears I think we all share is break ins.  However, having a security system on each rental can add up.  An old property manager of mine had heard of a portable security system that you could take from rental to rental and pay a small monthly fee for monitoring.

However, he can't remember what it was.  I've done a google search and came up empty.  Has anyone else heard of this and/or used something like this?  I'd greatly appreciate knowing if there was something like this on the market!  Thanks in advance!