The mylar bags feature a sealing strip Zipper Closure to keep water and moisture dust or any odors out when sealed, and the sealing strip is very , you will never question whether the mylar bags are open or closed The smell proof bags is mylar and foil material, means your food stay fresher for than a regular Zipper Closure bag. Mylar bags is suitable for packing, storing, , sampling, and sorting. This resealable bags can coffee, beans, , sugar, rice, baking, cookie, tea, nuts, dried fruit, dried flowers, , , medicine, herbs, spices, and much more food or decorations. The mylar bags can heat sealable, double sided black heat seal bags. The mylar bags can work with various food sealer machines for extra protection. size:7*10cm Material:Aluminum foil colour: black Package Contents: 100 * Flat Food bags Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.