Kimble KIMAX 28014E-1000 Class A Colorware Volumetric Flasks with Green Marking Area & [ST] Glass Pennyhead Stopper, Calibrated 'To Contain'. The Colorware flasks are brighter in appearance than traditional glassware with white markings. These flasks are also commonly used to help reduce cross-contamination and for easy identification of glassware between labs. Flask has a single graduation ring blasted on the neck, calibrated "to contain". A Standard Taper ground glass stopper is supplied, along with a durable, color, matte finish marking area for use with an ordinary pencil. Replacement stopper is 850100. Designed from ASTM Specification E288, Class A requirements. Manufactured from 33 expansion, low extractable borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class A requirements.