These plugs are used to prevent rust and corrosion in engines while in storage. Contain silica gel which turns from blue to pink when moisture is absorbed. Reusable and refillable. The pink silica gel may be reactivated (after removing from reservoir) by heating for 16 hours at 250°F.
DISCOUNT: LESS 10% ON 25, 15% ON 50, 20% ON 100.