Wynns Engine Oil Stop Leak is an oil-soluble supplement designed to stop and prevent engine oil leaks without the need for dismantling. It revitalizes rubber and neoprene seals found in crankshafts, camshafts, and valve stems. This product is compatible with all mineral, synthetic, single- and multigrade oils, making it suitable for both regular and low SAPS applications. Importantly, it does not harm catalytic converters and does not affect the oil's quality or viscosity. Each unit is sold individually.