... :Plain,ZP,YZP,Black,HDG,Nickel Size:4mm to 200mm Retaining ring Material: Carbon steel, mild steel, stainless steel,brass,aluminum Finish ... insert lock nuts, cap nuts, slotted nuts, rivet nut.WASHERS: flat washers, spring washers, lock washers.SCREWS: machine screws, self tapping ... drilling screws Welcome to inquiry, please contact me 0086-13375150195, Retaining ring