Parafilm M, 4 x 250 ft

Parafilm M is a semi-transparent, flexible,
thermoplastic, and highly waterproof sheet material. It
is practically colorless, odorless and is approximately
0.13 mm in thickness. It is permeable to gases, but
highly insensitive to moisture loss and moisture
absorption, thus making it ideal for protecting the
contents of broth tubes, flasks, culture tubes, and petri
dishes. The permeability of either oxygen or carbon
dioxide should not be affected at different relative
humidities because of the low water permeability and
insensitivity of Parafilm to moisture vapor.