Parafilm M is a semi-transparent laboratory and general-purpose sealing film. Sticks instantly to itself and is ideal for sealing culture tubes, flasks, petri dishes and virtually any laboratory vessel or instrument. It provides protection to your samples from outside air, gases, alcohols, most acids, and lightly concentrated alkalies. Film thickness: 0.005". size: 4" x 250 ft. Rolls. 1 roll/Pack; 12 packs/case. Capitol #: p1540-5.