These 9" x 12" 3-mil slider zipper locking bags can be described with one word, "Convenience". These Easy to use slider bags open/close feature is what has made the SliderLock bags so popular. These White Block Lock Top 9 x 12 .003 mil slider lock seal zipper locking bags great for a wide variety of applications such as, Hospitals, Restaurants, Kit Manufacturers, Document Storage, Agriculture, Airports, and in schools because they are simple enough to operate even for small children. These 9in. x 12in. 3mil slide zipper bags close quickly and easily the first time, and every time. All WhiteBlock Lock Top .003 mil slide lock bags are made of Made of Low Density Polyethylene (LDPE) resin and meets FDA/USDA specifications for food contact.