IIRC, they originally stopped making these due to "unwanted, terminal disassembly", meaning they were breaking, apparently quite catastrophically. Were they made of too brittle a material, and/or too thin in a critical area, to function in the high-impact and vibration environment of a muzzle device used on short barrels? I believe that the originals were made of some variation of stainless steel.
ETA: Apparently these are "Gen 2", so most likely they have "worked out the bugs" from the earlier variant. They are made from 17-4 stainless. They certainly do look good in the pics, and their product description is on point.