213U5 Karter Scientific Reagent Bottle, Amber, 250mL, Narrow Mouth w/Stopper Size 27, 70mm x 135mm Narrow mouth reagent bottles with ground glass stopper ideal for solids and liquids All glass bottle and stopper made from 3.3 borosilicate glass helps prevent changes in pH levels and maintain content purity Features no-drip pour lip for easy pouring of contents Ground glass stopper fits securely Unit can be autoclavable / sterilized