Hy-Per Lube makes available Hy-Per Lube Zinc Replacement Additive (ZRA). Hy-Per ZRA is safe for use in all engines, even those with catalytic converters. This product will provide maximum wear protection for cams and lifters in flat tappet cam design engines, according to the company. Hy-Per Lube Zinc Replacement Additive also maintains a strong oil film at high temperatures. It reduces cold start wear after long periods of shut down. The additive is environmentally safe; contains no heavy metals and will not harm emission controls or catalytic converters. It does not contain Zinc or Phosphorous.