The Wheaton Magna Flex Spinner Flasks feature a flex-type, bulb-shaped glass impeller that rotates from a fixed position above liquid level around an indentation in the base of the flask. Primarily designed for use with microcarrier cultures, this unique stirring system increases stirring efficiency and provides a gentle, even circulation throughout the flask while keeping the beads in suspension. Wheaton Magna Flex flasks are available in sizes ranging from 125 to 6000 mL and are fully autoclavable. The patented Wheaton Magna Flex impeller produces high-yield cultures by maintaining even circulation while keeping microcarriers in suspension. Slow acceleration and slow stop from the Wheaton Micro-Stir® stirrer prevent cell detachment. Sidearms on Magna Flex and Celstir® vessels 500 mL and larger were widened to accommodate monitoring and control devices or media inlet/outlet lines. The flasks are borosilicate glass with two large sidearms with screw cap closures for easy sampling. Units 500 mL and larger have 45 mm sidearms to be used as an air vent, media inlet or outlet, inoculation port, pH probe inlet, etc. All flasks have been proportioned to provide a head space ratio of 1:1 or greater. A removable stainless steel pin immobilizes the impeller during handling or decanting to prevent damage to cells or microcarriers. Sizes 125 to 1000 mL are graduated in 50 mL increments; sizes 3000 to 8000 mL are graduated in 500 mL increments. Sizes 500 mL and larger can be used with the Vented Cap (W240751).