The Rein Crankcase Return Hose - ABV0178 is a replacement hose designed for use in automotive engines. It is used to return oil vapors from the crankcase back to the intake system, preventing them from escaping into the environment. This hose is made from durable materials and is designed to withstand high temperatures and pressure. It is compatible with various makes and models of vehicles and is an essential component for maintaining proper engine function.