Penrite Engine Stop Leak is an engine oil additive that has been specifically formulated to help control engine oil leaks commonly caused by old, deteriorated or worn oil seals and gaskets. Penrite Engine Stop Leak helps to rejuvenate worn seals thus improving oil seal performance, reducing leaks and oil consumption. Penrite Engine Stop Leak is easy to use, simply add 1 bottle at any time for up to 6 Liters of engine oil, use every service for maximum benefits. Penrite Engine Stop Leak is compatible with all Mineral, Semi Synthetic and Full Synthetic engine oils. Not recommended for use in petrol engines with VVTI or Diesel Engines that have oil operated injector pumps.