Top quality piston kits featuring superior ring seal, bore compatibility, quiet running and longer life span 2,000 hours of durability testing behind every piston Auto fit coating is a permanently bonded, moly based coating process, designed to last for the life of the piston Accurate to 30 micron thickness to deliver tight piston to sidewall clearances for ultra quiet operation Gas nitride coated rings offer the ultimate compatibility with nickle silicone carbide-plated bores Big bore piston kits are intended for use with Revolution Performance Big Bore Cylinders