Lovibond Alka-M High Range Photometer Tablets, Alka-M HR Tablet, Range: 5 to 500 ppm, Orange, Composition: Adipic Acid 10 to 20%, non-hazardous components 80 to 90%, Format: Tablet, For Use With: Water analysis, MD600 colorimeter, Spectrodirect & Multidirect spectrophotometer, XD7000, and AquaPRO6, Method: Acid Indicator