Product can be used for up to 2 years after bottle has been opened. Bottle: To measure small quantities: Remove small cap & seal (on long neck) squeeze bottle to desired level, and pour. To measure large quantities: remove large cap & seal, pour (measurements on bottle side). Usage: 1 oz treats up to 2-1/2 gallons of fuel. Use Sta-Bil only with fresh fuel, and keep gas can or tank 95% full to avoid condensation build up in tank during storage. Run engine for 5 minutes after adding product to treat entire fuel system. Product does not contain alcohol.