The roller wheel used in Schubeck Rocker Arms is made of a special composite material that is harder than the valve it contacts.  Because it is highly polished, it will not wear the valve tip.  Also, this solid wheel (no axle) weighs only two grams compared to 21 grams of weight of a steel wheel and axle. There is a savings of 19 grams with Rocker-X.  That is equal to throwing away the weight of a titatainum valve spring retainer from each valve assembly. This will improve acceleration and increase horsepower.