Reusable silicone bag. 300mL. *The Porter Bag is the latest in storing snacks, ingredients and leftovers. *These silicone bags are not only secure yet easy to open, they're also a stylish and eco-friendly alternative to the disposable plastic bag. *Unlike ordinary disposable plastic zip lock bags, the Porter Bag is made from microwave and oven-safe silicone which means you can cook or reheat food directly inside the bag.