Nasco Whirl-Pak® blender bags are extra heavy-duty, precision-made, polyethylene bags for use with laboratory bag blenders. With tab and wire frame which allows the bag to be held open, and a writing panel. The bag can be sealed by pulling the tabs and whirling the bag around the wire or folding the top edge over several times. The wire tabs then can be folded back to hold the bag closed. Ethylene oxide gas sterilised. With curved seam at the base for use with circulator-type, bag blenders.