From the product description, check product page for current description, price and availability:

• Multi-purpose: these mylar bags are suitable for storing food, coffee, tea, dried food, dried fruit, etc.; Suitable for packing, storing, sampling and sorting
• Function: you can use heat sealing machine (not included) to seal away from light and oxygen barrier, prevent food being exposed to air, light, odors and moisture, these foil pouch bags can extend the storage time of food
• Feature: these foil mylar bags with an aluminum-foil layer can prevent tearing and destroying, puncture resistance, not easy to break leakage, to meet your long term dry storage requirements
• Easy to use: there is a U shape tear on the side for easy tear, save time to find a knife or scissors, sealable with hot iron, heat sealing ensures a long term

From HBF: Make sure the components you use are compatible and rated for your intended application.  Contact manufacturer with questions about suitability or a specific application.  Always read and follow manufacturer directions.