Double track zippers extend the width of the bag and keep products clean and free from moisture and leakage 2 tracks lock together to provide an even stronger seal than regular seal-top bags. Reclosable bags can be reused. Meets FDA and USDA specifications for food contact. Sizes listed are the inside usable dimensions of the bag. Office Depot(R) Brand 4-Mil Double-Track Reclosable Poly Bags, 10in. x 12in., Case Of 1,000 is one of many Reclosable Poly Bags available through Office Depot. Made by Office Depot.