Nalgene DS4101-0500 Polypropylene 500mL Filtering Flask with Angled Tubulation Capacity: 500ml; fits tubing I.D.: 1/4 to 3/8 inch (6.4 to 9.5mm); stopper number: 7 Material: polypropylene Molded in one piece to withstand full vacuum to 30 inches Hg The 45 degree angle of tubulation prevents tipping Non-graduated; has an oval marking area; barbed adapter; autoclavable