I just got back from an Elk Hunting trip in CO and one of the guy's in our group had a gun sling that would not slip off his shoulder. He couldn't remember who made the sling or how to get in touch with them, but this sling had a neoprene? no slip surface and would not slide down his shoulder. He said he thought it cost b/t $25-30. He said he bought it at a gun show but it's also been advertised on some of the hunting shows on the Outdoor Channel. Anyone ever hear of this sling??