Disposable tissue culture flasks are made of high quality polystyrene for optical clarity and distortion-free examination. Plasma treated to provide optimum cell attachment and maximum yield. Constructed with stacking ribs for efficient storage in your incubator. Cap style allows open or closed incubation. The blue plug-seal caps feature an “open” position indicator. Graduated in standard media quantities from 10 to 100 ml. A frosted writing area makes labeling fast and easy. With caps.