I just spoke with Ralph Helms of WKA, and the reason they approved the ARC first is that ARC is the only company.."At This Time" that can supply enough flywheels to meet demand. Mr. Helms said that other flywheels would be looked at for approval at the next board meeting in March.The price of the ARC flywheel has been reduced not raised, and according to ARC will be reduced more as demand increases.The Only WKA Legal flywheel at this time is ARC Part # 6608. It weighs 4 lbs, 14 oz. Just passing info on. Thanks, David