Starbrite Sea Safe Antifreeze -200 Concentrate

Winterizing antifreeze for engines, potable water systems and heads. It is a virgin propylene glycol formula, so it is non-toxic and safe to run through a drinking water system, and the additive package protects the aluminum, copper, brass and solder in a marine engine without attacking rubber, seals or hoses.

• Non-toxic virgin propylene glycol formula
• Ready to use, or dilute to your required protection level
• Safe for all engines including aluminum
• Corrosion inhibitors for metal engine components and seals
• Dyed bright blue so you can see when it has come all the way through a system
• Gallon size, concentrate

Run it until you see solid color coming out the exhaust or the faucet. Antifreeze that only made it halfway through the system is the same as none at all.