Autoclavable volumetric flasks made of polypropylene or transparent polymethylpentene with polypropylene screw closure. Every flask is gravimetrically calibrated for filling and for pouring at 20°C. No meniscus, which makes for easy, precise read-offs. Oval marking spot. Non-contaminating screw closure without insert. Leakproof. Volumetric flasks are compliant with ISO standard 384 and ASTM standard E 288.