This 250mL PYREX® low actinic flat bottom boiling flask has a full length outer 24/40 standard taper joint, but with a shorter neck. Low Actinic stained glass provides protection for materials sensitive to light. The protective color is an integral part of the flask, which retains the mechanical strength, chemical stability, and thermal resistance of PYREX® labware. Manufactured from borosilicate glass Code 7740. The normal working temperature for this PYREX® boiling flask is 230°C. Reusable. Material: Borosilicate Glass Code 7740. Capacity: 250mL. Flask Style: Boiling. Flask Shape: Flat Bottom. Top Style: Standard Taper Joint. Neck Style: Short. Stopper Style: No Stopper. Flask Feature: Low Actinic.Standard Taper Center Neck Joint: 24/40. Height: 135mm. Outer Diameter: 82mm. Corning® #: 54100-250.