These 4" x 6" 6-mil zip lock bags are Our thickest ziplock bags and are ideal for packaging your heaviest items in these bags. These heavy duty Clearzip 4 x 6 .006 mil ziplock bags greatly reduce the possibility of tears or punctures and protect the contents under heavier use and re-use. The side-welded 6mil zipper top bag seal reinforces the zipper for added strength and insures these 4in. x 6in. 6mil ziploc bags are resealable and reusable, no matter how many times the bag is opened and closed. All Clearzip 6-mil plastic zipper bags meet FDA/USDA specifications for food contact.