Amber Glass Reagent Bottle 250ml Narrow Mouth Made in China. Reagent Bottles are useful for storing both liquids and powders. These bottle mouth and stopper stem are machine-ground. This glass-to-glass joint is an air-tight seal without the use of a rubber or cork stopper. Please note –REAGENT BOTTLES are made of Soda-Lime glass, a common glass used in most beverage bottles. Our laboratory glassware is reasonably priced and a great choice for heavy use in schools, shops, and laboratories where some breakage can be expected. Our glassware is a FRACTION of the cost of Corning or Kimble/Kontes. Customers seeking an extremely high level of flawless quality should purchase these brands. Our glassware can contain small blemishes or bubbles that do not affect the function of the bottle.