Chromerge® Glass Cleaner leaves surfaces chemically clean, protects glass and aids in creating a perfect meniscus. Each bottle contains 25ml of chromium trioxide in solution which, when mixed with a 4.1kg (9lb) 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. No Air Shipment. 6 x 25mL/Pack; 4 Packs/Case. Bel-Art# F170890000. Capitol # C5350.