Prime Conventional Green antifreeze+coolant (ready to use) is the original coolant. This low silicate formula, when used as directed, will provide protection for a minimum of 1 year. Prime will guard against temperature extremes and the affects of rust, corrosion, and premature water pump failure. Meets or exceeds ASTM requirements for cars, light duty trucks. Prime green should only be used on vehicles that have been using conventional fluids, many vehicles moved to extended life coolants in 1990s.