Zplus brand premium ZDDP Zing engine oil treatment. For restoring Zinc protection to modern engine oils when used on older vintage, historic or racing vehicles. 4oz bottle, treats 4-5 quarts of oil. Two bottles needed per service on most air-cooled Porsche engines. Ideal for most 911, 930, 964 and 993 vehicles. 

Please note: Intended for use on pre-OBD off-road and racing vehicles. Not for highway use.