Shrink Seals are colorless, transparent cellulose bands that are oxygen permeable. Used for sealing Petri dishes or test tubes to safely contain pathogenic microorganisms. Dries in under 30 minutes at room temperature and extends the shelf life of sensitive plates. Bands need to stay moist in sealed container until use. 92 x 25mm available in 400 seals/pkg and 6000 seals/pkg. 21 x 20mm seals available 1000/pkg.