Yamaha Rhino 660. 12 Point Chromoly Head Nuts. Nuts Are Machined From Billet High Tensile Steel And Heat Treated. This is a bolt on kit with no machining required. Both Nut And Stud Are Black Oxide Treated For Enhanced Corrosion Resistance.
Have not installed studs order for a 660 rhino received studs for 700 rhino. Don't know if compatible. Will reorder if not comparable. Good quality need tech support.