Yes they do. I think they call it "isocore". It's an 8# maul. I had a chance to try one that @svk brought over to my place. It's a pretty nice tool. I think they make a sledge also. Same warranty as the x27. I think Steve said that the steel seemed harder than on the x27 and was holding up to splitting on the ground nicely.
Got one last week on eBay for 45. Went out & split a dozen rounds of tamarack, thought it worked real well. Won't replace the hydraulic splitter but it's a nice addition to the truck for the big heavy rounds.