PYREX 25 mL Nessler color comparison tubes are specialized glass cylinders designed for colorimetric analysis. While many manufacturers produce these, Pyrex (by Corning) is a standard choice for its high-quality borosilicate glass.

Key Specifications

• Dimensions: Typically around 165–180 mm in height and 20 mm in diameter.
• Bottom Design: Often feature a shadowless bottom to transmit undistorted light, preventing dark spots during visual inspection.
• Graduations: Usually feature a single calibration mark at the 25 mL level for standardized testing, though some models may include a 10 mL mark.
• Stopper/Seal: Many variants include a glass stopper