High Performance Sealing Solution 1 Gallon High Performance Concentrate Sealing Solution ( 1 Gallon) is the most effective solution to solving troubled envelopes sealing issues. It comes in a concentrate; just add water Whether high speed inserting, envelope sealing, stamp affixing or packaging tape dispensing, PI-High Performance Sealing Solution seals tight every time A combination of active ingredients fight bacteria and algae growth FREE SAME DAY SHIPPING! Comes with 4 ounces of concentrate- mix slowly with water to make 1 Gallon High Performance Sealing Solution.