These "Jumbo" vacuum sealing pouches from VacMaster (model 947320) measure 15"W x 18"L and are designed to be used with external (i.e., non-chamber) suction vacuum sealers. Vacuum sealing foods keeps them fresh for as much as 5 times longer than other storage methods. These pouches are 3 mil thick and are great for the storage of meat, fish, dry foods, cheeses, etc. 80% polyethylene & 20% nylon, the textured mesh layer of the bag permits complete air removal and a tight seal. Boilable, microwavable and great for sous vide. 50 bags come in this package.