Another great product from Neptune. Having experienced an aquarium failure with my last aquarium, I can tell you this is a must have piece of equipment. It is fairly unobtrusive, and is quite sensitive. your Apex unit will send you an alarm notification email if it detects moisture, or you can have it trigger an audible alarm if you attach a separate alarm to your system. I had this in my basement with my garbage can of rescued live rock from my previous aquarium and because of this I came to know that I had a yet unidentified plumbing issue with my floor drain.