Disclaimer: I received this product for no charge through the Vine program.These small mylar bags are exactly what the Amazon listing claims. They are tough (I could not tear one apart with my hands), airtight, lightproof, waterproof, and resealable. They are great for storing small items or distributing small quantities of granular material such as powders, herbs, or seeds. I found them useful for small electronic components which tend to poke through ordinary zip-lock plastic bags.The bags measure 4 x 5 inches. I measured their thickness with a digital caliper and the mylar is 5.5 mils thick (just shy of the claimed 6 mils). Packing a bag as full as possible with corn kernels and sealing it, I determined that the bags hold 100 cc's or just over three fluid ounces. When full, the pleat at the bottom of the bag can be pulled apart and the bags will stand upright. The zip lock seals easily but is robust and takes a moderate amount of effort to open.If you need such a product, this is an excellent choice.
