Always wear appropriate gloves and safety glasses when handling fuel. Simply peel off the old nitrile “C” seal from the pourer of your Pro Quip Plastic Fast Pour Fuel Can. Replace the old seal with a new nitrile “C” seal from Pro Quip, wrapping it around the protruding ridge of the pourer from where it was removed. Seals positioned below this ridge will not adequately seal against the stopped disc and will cause the can to leak. Seals positioned on the stopped disc will both not seal the can for either pouring or storing. This will also stretch the nitrile rubber and cause it to be less effective if then placed correctly.