Thrift's amazing SUPER-PRO Acid formula is a heavy-duty acid drain cleaner. It is a 95% Virgin sulfuric acid without all the nasty side effects typical of other acids. If you are going to sell sulfuric acid to your customers, shouldn't it be the safest one. Thrift SUPER-PRO Acid is for professional use only. SUPER-PRO is sold exclusively to the wholesale plumbing market.