Product Code Product Description PRS-A0885 Reference Colours Glass PRSGG-1705 Graduated Impurities Test, Glass Bottle 500 ml, ASTM PRSGG-1710 Graduated Impurities Test, Glass Bottle 1000 ml, ASTM PRSGG-1720 Cylindrical Glass Bottle with Cork Stopper, for Organic Impurities, 450 ml,EN PRSGC-0840 Sodium Hydroxide 1 kg The Reference Colour Glass consists of 5 organic glass scales mounted in a plastic holder, which is used for the comparison of the colour results from the relevant test. The 500 ml and 1000 ml capacity Graduated Glass Bottles are used for making reference standard colour and test solution according to the ASTM standard. PRSGG-1720 450 ml Cylindrical Glass Bottle is used for determination of organic impurities as required in the EN standard.