Weber Scientific Sterile Sampling Bags are sterile, single service bags made of heavy transparent polyethylene. Capacity of each bag is measured when the bag is closed, and the tab is folded over three (3) times. Volume and dimensions are approximate. Bags should not be used at temperatures above 180°F (82°C) however can be frozen to any temperature. The bags featuring a write-on strip have a paper-like, smear-resistant finish and can be written on with any ordinary ballpoint pen, pencil, or marker.