i ink you will be surprised that some of the so-called restoration batteries are made the same way.
there is only one company that makes the hardrubber case for the restoration batteries ,older technology, so anybody making a restoration battery has to have them manufactured thru them. That's the problem there are to many pieces to to the agm resto batteries that are outsourced and only 2 battery manfactures in the USA . thanks EPA!
im not a big fan of agm's because of the maintenance and warrantee issues. heck the military won't use them, not dependable.