Snake oil, trying to profit from Harley's sumping problem. This product is unlikely to affect sumping on M8's, and I'd be surprised if it had any real benefits. If you have oil carryover into the air cleaner on older models, update your breather valves to the latest version, don't expect this product to magically fix that problem either. This product basically makes your bike similar to a 1950's model bike or car, where crankcase vapors were vented directly to atmosphere which added greatly to air pollution. Gas engine vehicles have been required to control those emissions since the 1960's, and the method used has been through venting the crankcase to the intake system. It's worked just fine for decades, and it doesn't seem to negatively affect those 500 and 600 horsepower cars Ford, Chrysler, and GM have been building and selling, much less the less ambitious vehicles offered for regular folks.
JMHO - Jerry