Closures for containers and methods for using same are provided. In a general embodiment, the present disclosure provides a closure having a top portion (12), a bottom portion (14) and a side portion (16), an aperture (18) extending though the closure, a projection (20) extending from the closure and at least two rib members (36) on an interior of the projection. The projection may also include a cover. In another embodiment, a method for using a closure includes inserting a spike member into a projection, piercing a membrane (28) that hermetically seals a medical container, pushing rib members within the projection to center the spike member inserted into the projection, and tearing the membrane to create a vent hole in the membrane.