Soda-lime glass. For the determination of oxygen dissolved in water. The measured volume is indicated to a precision of 2 decimal places. White labelling area. Solid, obliquely cut standard-ground glass stopper, can be secured with a fastening clip. Each flask is calibrated with its own stopper; hence, stoppers and flasks are not interchangeable. Each flask and its stopper is marked with a unique matching identification number. Soda-lime glass. For the determination of oxygen dissolved in water. The measured volume is indicated to a precision of 2 decimal places. White labelling area. Solid, obliquely cut standard-ground glass stopper, can be secured with a fastening clip. Each flask is calibrated with its own stopper; hence, stoppers and flasks are not interchangeable. Each flask and its stopper is marked with a unique matching identification number.