Parafilm M Sealing Film, 250' L x 2" W, Pliable, Self-sealing, Moisture-proof, Thermoplastic Sheet Material, Substantially Colorless, Molds and Seals Itself Tightly Around Test Tubes, Flasks and Instruments and Objects With Irregular Surfaces
Highly insensitive to moisture vapor, loss and absorption, yet permeable to gases sufficiently to make it ideal for working with culture media.