More durable than Molly and other coatings. Recommended for all uncoated pistons for tighter installation clearance, reduced friction and longer life. Note that many of our flat top pistons come precoated at no extra charge. All Domni, domed and stock rod pistons are uncoated. This aftermarket graphite coating is superior, longer lasting and extends the piston life.  Our domed, extra high compression flat top, Domni and special order pistons are not coated.  If the pistons you order already have a coating then you will be refunded. Image of piston coating after 7 racing seasons.