3 mil Vacuum Pouches
These bags are ideal for storage and low temperature "sous-vide" style cooking. They are rated for a temperature range of -58 F° to 176 F°, and have superb clarity.
Comes in a case of 500 12" x 16" bags. 3 mil thick. They can be used with chamber vacuum packaging machines P371
See The Basics of Sous-Vide Cooking