I had one on my 750 in the 70's. It was 2-piece made of ABS plastic and had a squeeze-bottle on top which put oil on some felt which ran atop the chain. I welded up a little oil tank with the works from an oil can to pump oil onto the felt. In those days the 750 was a touring bike and about every 100 miles I'd wait'll I came to a small town, give the tank a couple of pumps and drive very slowly through town while the oil coated the chain. It worked pretty well but was still a bit messy. Nowadays I use the goldwing for touring. I still have all the stuff and might put it back on someday but for now I'm squirting the wax stuff on.