California Proposition 65: This product contains a chemical known to the State of California to cause cancer. California Proposition 65: This product contains a chemical known to the State of California to cause birth defects or other reproductive harm. Maintaining your truck can be easy as 1-2-3 with this ignition sealer from Gunk. This 6 oz. clear ignition sealer comes in an aerosol can container. Its applications include: Aerosol forms an insulating film on spark plugs, Sealer-Aerosol forms an insulating film on spark plugs, wires, distributor heads, ignition and generator connections, and other components to help waterproof motors and protect against drown-outs.