Patent attributes
One aspect of the invention provides a cap comprising: a plane defining an opening and a slidable closure adapted and configured to seal the opening. The slidable closure includes: a projection extending above an external surface of the plane and a flexible seal coupled to the projection and located on an internal surface of the plane opposite the projection. The flexible seal includes: a connection portion coupled to the projection; a sealing portion having a profile that is complementary to a shape of the opening; and a flexible hinge adapted and configured to bias the sealing portion against the internal surface. Another aspect of the invention provides a container assembly including: a container and the cap as described herein coupled to the container.