Lyph-Seal Sample Bags, crafted from durable PET/PE, feature a sanitary zipper-seal design that ensures maximum protection for your samples.These flexible containers conform to the shape of your samples, creating an effective vapor barrier that blocks humidity and significantly extends shelf life.Designed for seamless use with the Lyph-Seal Tray Dryer system and compatible with most commercially available impulse sealers.Freezer safe.Do not microwave or boil.