Reusable Sandwich Bag. The pinch press™ seal makes this bag airtight and leakproof. Ideal for food, travel, school and more. Made of 100 % pure platinum food-grade silicone. Unlike plastic bags, Stasher contains no petroleum, no PVC and no latex, & is BPA and BPS free, so it's good for us and our planet. This easy-to-clean, reusable bag is freezer, microwave and dishwasher safe.