One half gallon (64 oz total) of ready to use sealing solution includes heavy duty pump. For use in all DM Series Mailing Systems. Cheaper than the brand name Pitney Bowes. Our sealing solution is superior to ez seal sealing solution, which is Pitney Bowes sealing solution. Ez seal solution is higher priced and does not use our deionization process for envelope sealing. Our sealing solution is clear of all minerals and impurities.