Procomp Electronics piston rings are designed to stand up to the rigors of racing and high-performance street use while providing long-lasting life. Procomp Electronics piston rings feature Plasma-moly coated top rings that seal against blow-by when the piston rocks in its bore, tapered secondary rings that seal against the oil control ring's upper surface for excellent oil control, and 3-piece oil rings with stainless steel expanders that provide accurate tension without the loss of any horsepower.