The Corning 1L and 3L spinner flask body is constructed of polystyrene, paddle and shaft from polypropylene and caps from high density polyethylene. All are made of USP Class VI and ISO 10993-18 compliant materials. Extended paddle design ensures constant top-to-bottom motion of the liquid without having to adjust the height of the paddle. Bottom contours on the paddle hug the shape of the flask, eliminating dead spots. Two wide neck openings for easy pouring; easily accept a 100mL pipet. Vertical side baffles break up laminar flow - ensures better mixing and maximizes cell production. Each system is supplied individually double bagged. Sterilized by gamma irradiation; have the highest Sterility Assurance Level (SAL) of 10 -6 and meets USP XXIV:71 Bacteriostasis, Fungistasis and Sterility Standards. Single use only. Flasks cannot be autoclaved or resterilized with alcohol. Any attempt to do so will result in degradation of the materials.