Abstract: A filtering device for a beverage container with a tab opening system, which acts as a protector for a drink opening of the beverage container, allowing a user to drink through it. The device is not manually activated, and prevents entry of insects or foreign objects, while at the same time filtering beverages enclosed in the container. This filtering device consists of a concave net filter in the shape of half of an egg, which is placed underneath a shearable tab portion of the tab opening system of the container, and is fastened into place by three rivets.