Borosil Amber Reagent Bottles, Plain, Narrow Mouth, Graduated 500 mL CS/10. Borosil Amber Reagent Bottles, Plain, Narrow Mouth, Graduated with Interchangeable Flat Head Solid Glass Stopper ISO 4796-2 Ground neck Borosilicate glass Durable Matt finish enamelled area for marking 500 mL CS/10 Material: 3.3 Borosilicate