These borosilicate glass replacement spinner flasks are for use with caps and stirring mechanisms from Cole-Parmer® spinner flask assemblies. They incorporate a unique base design, which in cooperation with the bulb-ended glass stirrer rod (not included), ensures that cultures are lifted into suspension at the lowest possible speeds. The flask is silicone-encapsulated to reduce the possibility of cells attaching to and growing on the surfaces. Culture vessels come calibrated, and have two side ports and a central filling port. They are suitable for repeated autoclaving at 121 °C (250 °F) and 15 psi for 30 minutes. These flasks do not include caps or stirring mechanisms and are intended as replacement flasks only.