Nalgene™ burets are crystal-clear so levels of colorless liquids are easily read. Stopcock is leakproof, with self-lubricating PTFE TFE plug. Durable acrylic body with polymethylpentene tip make it excellent for general use, schools, industrial labs and field use. Graduated. Unaffected by dilute mineral acids and bases except hydrofluoric acid and ammonium hydroxide. The pH range of 1-14 is ideal and up to 5% wt/wt of acids or 30% bases can be used. Not designed for exposure to alcohol and organic solvents. Individually calibrated to meet the accuracy requirements of ASTM E287.