Wiseco 8950XX Ring Set: Automotive. Buy Wiseco 8950XX Ring Set: Piston Rings - ✓ FREE DELIVERY possible on eligible purchases. 1mm (.039") Ring: Stainless steel, gas nitride, barrel faced 。 1.2mm (.047")Ring: Cast iron, phosphate coated, taper faced, under hook 。 2.8mm (.110") 3 piece oil assembly: Stainless steel flex-vent spacer, nitride rails 。 1mm (.039") Ring: Stainless steel, gas nitride, barrel faced. 1.2mm (.047") Ring: Cast iron, phosphate coated, taper faced, under hook. 2.8mm (.110") 3 piece oil assembly: Stainless steel flex-vent spacer, nitride rails. 。 。 。