Chromerge® Glass Cleaner leaves surfaces chemically clean and aids in creating a perfect meniscus. Eliminates hard scrubbing and safeguards glass from breakage. Each bottle contains 25mL of chromium trioxide in solution which, when mixed with a 4.1kg (9lb) 2.50 liters container of sulfuric acid, makes a highly efficient cleaner. The mixture is then storable and can be re-used until it becomes green, indicating loss of effectiveness. Not for use with plastic. Packaged six 25mL bottles per box, 4 boxes per case.