But they make it hard to find on their website.

 

Here's a thought, although maybe not a good one.  An altimeter in the cabin that is not plumbed into the pitot-static system will indicate cabin altitude.  I've seen digial altimeters; maybe there's one that allows setting altitude alerts.  If the cabin altitude goes above 10K feet, or whatever you choose, you know you have a problem. 

 

Tom Gourley