AS is + Home Warrantee?

[Don Hines]

I know a home warrantee is just an insurance policy.
I am going back and forth on a FNMA property. They countered back that the property is sold as is. But, they are offering a home warrantee.
The house has some foundation sill plate rot, plus uneven floors from water damage. I would never dream of asking for a warrantee specially since it kind of counters the "as is" clause.
What can I expect this warrantee to cover?
Thanks
Don