Translucent flask is supplied with tapered polypropylene stopper with an individually calibrated graduation line. The product is manufactured to Class A tolerances as defined by ISO 1042. They are supplied with an imprinted lot number and certificate. These flasks may be autoclaved to 121°C without affecting the graduation tolerance. Recommended routine cleaning up to 60°C will preserve graduation markings. Height dimension is for flask only, without stopper.