That was the SSTs. I hated those tires. Ran them for about 15,000 miles on my 98 3/4 Cummins I had, ended up selling that truck before they ran out fully, but by 15,000 miles, they were over halfway thru their wear life. Loud as heck too which is saying a lot on a straight piped cummins diesel. And they didn't perform well in snow at all, which i was surprised about. On highway, loud, skaty tire.