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 121ºC without affecting the graduation tolerance. Recommended routine cleaning up to 60ºC will preserve graduation markings. Height dimension is for flask only, without stopper.